Korg Poly800/EX800 Users

From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
Behalf Of cc0919ship
Sent: Saturday, January 19, 2013 9:32 PM
To: korgpolyex@yahoogroups.com
Subject: [korgpolyex] Frozen Poly 800

 

  

Hello all,

I'm wondering if you can help me out. I recently acquired a broken Poly 800
(original, not MKII.) It powers up, but immediately after powering up, the
screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do
not make noise. If I turn up the volume the whole way, I can hear the filter
sweeping up and down. Here's where it gets interesting - I plugged in a MIDI
keyboard, and when I play notes with the MIDI keyboard, the 800 makes static
noises, and the last value on the screen increments by one.

I opened it up, checked the tactile switches (all seem fine.) I also
replaced the internal CMOS battery. I was under the impression that MKI 800s
didn't have this, so the main board may have been replaced by someone along
the line.

Anyway, has anyone had a problem like this and could help me out? It is
potentially one of the ICs, but I have no idea how to test them.

Thanks,

Christian

>
> That sound like the sequencer "enable" switch is on, plus you have no
> patches in memory. The sequencer switch on the back should be set to
> "disable" unless you are recording a sequence. Since this is an original
> Poly 800, there are several versions, some with a CR2032 lithium cell inside
> to hold the sound patches in memory when it is turned off, and some without.
> Since you just changed the battery, the memory will be empty or really
> random.
> 
> 1) Make sure the sequencer is switched to disable.
> 
> 2) You need to reload the factory patches or program one of your own for
> testing purposes.
> 
> If you've never loaded a patch audio file (.wav) on the "Tape In" jack of an
> early 80's synth, you may want to start by just programming one of your own.
> Unfortunately there are 50 parameters and you need to make sure all of them
> are set at something reasonable to get a sound. You might start by setting
> the Attack, Decay and Release to 0 and the Break P, Sustain to maximum (31)
> for Deg1, Deg2 and Deg3. I don't think the Slope matters when set this way.
> If you hear noise, then alter parameter 33 (Noise level) to see if it makes
> a difference. Oh, and parameter 41 (Cutoff) should be turned up full during
> this testing.
> 
>  
> 
> If the sequencer switch is really the main problem, then you should be able
> to get some sound out of it and we can help you get the factory patches
> loaded if you need help.
> 
>  
> 
> Don Backshall
> 
>  
> 
>   _____  
> 
> From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> Behalf Of cc0919ship
> Sent: Saturday, January 19, 2013 9:32 PM
> To: korgpolyex@yahoogroups.com
> Subject: [korgpolyex] Frozen Poly 800
> 
>  
> 
>   
> 
> Hello all,
> 
> I'm wondering if you can help me out. I recently acquired a broken Poly 800
> (original, not MKII.) It powers up, but immediately after powering up, the
> screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do
> not make noise. If I turn up the volume the whole way, I can hear the filter
> sweeping up and down. Here's where it gets interesting - I plugged in a MIDI
> keyboard, and when I play notes with the MIDI keyboard, the 800 makes static
> noises, and the last value on the screen increments by one.
> 
> I opened it up, checked the tactile switches (all seem fine.) I also
> replaced the internal CMOS battery. I was under the impression that MKI 800s
> didn't have this, so the main board may have been replaced by someone along
> the line.
> 
> Anyway, has anyone had a problem like this and could help me out? It is
> potentially one of the ICs, but I have no idea how to test them.
> 
> Thanks,
> 
> Christian
>

> the line.
> 
> Anyway, has anyone had a problem like this and could help me out? It is
> potentially one of the ICs, but I have no idea how to test them.
> 
> Thanks,
> 
> Christian
>

>
> The four "main" pins are nothing. They just ground the outer metal shell of
> the switch and keep it securely on the board. There are only two pins that
> matter, and you can see which two they are by looking at which pins actually
> have something connected to them. When enabled, these two pins are shorted
> together ( less than 0.5 ohms with an ohmmeter). When disabled, they are not
> connected to each other (greater than 10 Meg ohms between them).
> 
>  
> 
> Don B.
> 
>  
> 
>   _____  
> 
> From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> Behalf Of cc0919ship
> Sent: Saturday, January 19, 2013 10:51 PM
> To: korgpolyex@yahoogroups.com
> Subject: [korgpolyex] Re: Frozen Poly 800
> 
>  
> 
>   
> 
> Thanks for the suggestions. I took a look, sequencer was disabled. Perhaps
> the switch is bad? I'm not sure how to test it, it has 4 main pins, then 14
> smaller pins. I'm using a multimeter, but can't figure out what pins the
> switch is effecting.
> 
> --- In korgpolyex@yahoogroups.com  ,
> "backshall1" wrote:
> >
> > That sound like the sequencer "enable" switch is on, plus you have no
> > patches in memory. The sequencer switch on the back should be set to
> > "disable" unless you are recording a sequence. Since this is an original
> > Poly 800, there are several versions, some with a CR2032 lithium cell
> inside
> > to hold the sound patches in memory when it is turned off, and some
> without.
> > Since you just changed the battery, the memory will be empty or really
> > random.
> > 
> > 1) Make sure the sequencer is switched to disable.
> > 
> > 2) You need to reload the factory patches or program one of your own for
> > testing purposes.
> > 
> > If you've never loaded a patch audio file (.wav) on the "Tape In" jack of
> an
> > early 80's synth, you may want to start by just programming one of your
> own.
> > Unfortunately there are 50 parameters and you need to make sure all of
> them
> > are set at something reasonable to get a sound. You might start by setting
> > the Attack, Decay and Release to 0 and the Break P, Sustain to maximum
> (31)
> > for Deg1, Deg2 and Deg3. I don't think the Slope matters when set this
> way.
> > If you hear noise, then alter parameter 33 (Noise level) to see if it
> makes
> > a difference. Oh, and parameter 41 (Cutoff) should be turned up full
> during
> > this testing.
> > 
> > 
> > 
> > If the sequencer switch is really the main problem, then you should be
> able
> > to get some sound out of it and we can help you get the factory patches
> > loaded if you need help.
> > 
> > 
> > 
> > Don Backshall
> > 
> > 
> > 
> > _____ 
> > 
> > From: korgpolyex@yahoogroups.com 
> [mailto:korgpolyex@yahoogroups.com  ]
> On
> > Behalf Of cc0919ship
> > Sent: Saturday, January 19, 2013 9:32 PM
> > To: korgpolyex@yahoogroups.com  
> > Subject: [korgpolyex] Frozen Poly 800
> > 
> > 
> > 
> > 
> > 
> > Hello all,
> > 
> > I'm wondering if you can help me out. I recently acquired a broken Poly
> 800
> > (original, not MKII.) It powers up, but immediately after powering up, the
> > screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys
> do
> > not make noise. If I turn up the volume the whole way, I can hear the
> filter
> > sweeping up and down. Here's where it gets interesting - I plugged in a
> MIDI
> > keyboard, and when I play notes with the MIDI keyboard, the 800 makes
> static
> > noises, and the last value on the screen increments by one.
> > 
> > I opened it up, checked the tactile switches (all seem fine.) I also
> > replaced the internal CMOS battery. I was under the impression that MKI
> 800s
> > didn't have this, so the main board may have been replaced by someone
> along
> > the line.
> > 
> > Anyway, has anyone had a problem like this and could help me out? It is
> > potentially one of the ICs, but I have no idea how to test them.
> > 
> > Thanks,
> > 
> > Christian
> >
>

>
> Thanks. The switch appears to be working normally.
> 
> --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> >
> > The four "main" pins are nothing. They just ground the outer metal shell of
> > the switch and keep it securely on the board. There are only two pins that
> > matter, and you can see which two they are by looking at which pins actually
> > have something connected to them. When enabled, these two pins are shorted
> > together ( less than 0.5 ohms with an ohmmeter). When disabled, they are not
> > connected to each other (greater than 10 Meg ohms between them).
> > 
> >  
> > 
> > Don B.
> > 
> >  
> > 
> >   _____  
> > 
> > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > Behalf Of cc0919ship
> > Sent: Saturday, January 19, 2013 10:51 PM
> > To: korgpolyex@yahoogroups.com
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> >  
> > 
> >   
> > 
> > Thanks for the suggestions. I took a look, sequencer was disabled. Perhaps
> > the switch is bad? I'm not sure how to test it, it has 4 main pins, then 14
> > smaller pins. I'm using a multimeter, but can't figure out what pins the
> > switch is effecting.
> > 
> > --- In korgpolyex@yahoogroups.com  ,
> > "backshall1" wrote:
> > >
> > > That sound like the sequencer "enable" switch is on, plus you have no
> > > patches in memory. The sequencer switch on the back should be set to
> > > "disable" unless you are recording a sequence. Since this is an original
> > > Poly 800, there are several versions, some with a CR2032 lithium cell
> > inside
> > > to hold the sound patches in memory when it is turned off, and some
> > without.
> > > Since you just changed the battery, the memory will be empty or really
> > > random.
> > > 
> > > 1) Make sure the sequencer is switched to disable.
> > > 
> > > 2) You need to reload the factory patches or program one of your own for
> > > testing purposes.
> > > 
> > > If you've never loaded a patch audio file (.wav) on the "Tape In" jack of
> > an
> > > early 80's synth, you may want to start by just programming one of your
> > own.
> > > Unfortunately there are 50 parameters and you need to make sure all of
> > them
> > > are set at something reasonable to get a sound. You might start by setting
> > > the Attack, Decay and Release to 0 and the Break P, Sustain to maximum
> > (31)
> > > for Deg1, Deg2 and Deg3. I don't think the Slope matters when set this
> > way.
> > > If you hear noise, then alter parameter 33 (Noise level) to see if it
> > makes
> > > a difference. Oh, and parameter 41 (Cutoff) should be turned up full
> > during
> > > this testing.
> > > 
> > > 
> > > 
> > > If the sequencer switch is really the main problem, then you should be
> > able
> > > to get some sound out of it and we can help you get the factory patches
> > > loaded if you need help.
> > > 
> > > 
> > > 
> > > Don Backshall
> > > 
> > > 
> > > 
> > > _____ 
> > > 
> > > From: korgpolyex@yahoogroups.com 
> > [mailto:korgpolyex@yahoogroups.com  ]
> > On
> > > Behalf Of cc0919ship
> > > Sent: Saturday, January 19, 2013 9:32 PM
> > > To: korgpolyex@yahoogroups.com  
> > > Subject: [korgpolyex] Frozen Poly 800
> > > 
> > > 
> > > 
> > > 
> > > 
> > > Hello all,
> > > 
> > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > 800
> > > (original, not MKII.) It powers up, but immediately after powering up, the
> > > screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys
> > do
> > > not make noise. If I turn up the volume the whole way, I can hear the
> > filter
> > > sweeping up and down. Here's where it gets interesting - I plugged in a
> > MIDI
> > > keyboard, and when I play notes with the MIDI keyboard, the 800 makes
> > static
> > > noises, and the last value on the screen increments by one.
> > > 
> > > I opened it up, checked the tactile switches (all seem fine.) I also
> > > replaced the internal CMOS battery. I was under the impression that MKI
> > 800s
> > > didn't have this, so the main board may have been replaced by someone
> > along
> > > the line.
> > > 
> > > Anyway, has anyone had a problem like this and could help me out? It is
> > > potentially one of the ICs, but I have no idea how to test them.
> > > 
> > > Thanks,
> > > 
> > > Christian
> > >
> >
>

>
> Hello all,
> 
> I'm wondering if you can help me out. I recently acquired a broken Poly 800 (original, not MKII.) It powers up, but immediately after powering up, the screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do not make noise. If I turn up the volume the whole way, I can hear the filter sweeping up and down. Here's where it gets interesting - I plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard, the 800 makes static noises, and the last value on the screen increments by one.
> 
> I opened it up, checked the tactile switches (all seem fine.) I also replaced the internal CMOS battery. I was under the impression that MKI 800s didn't have this, so the main board may have been replaced by someone along the line.
> 
> Anyway, has anyone had a problem like this and could help me out? It is potentially one of the ICs, but I have no idea how to test them.
> 
> Thanks,
> 
> Christian
>

>
> Hello all,
> 
> I'm wondering if you can help me out. I recently acquired a broken Poly 800 (original, not MKII.) It powers up, but immediately after powering up, the screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do not make noise. If I turn up the volume the whole way, I can hear the filter sweeping up and down. Here's where it gets interesting - I plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard, the 800 makes static noises, and the last value on the screen increments by one.
> 
> I opened it up, checked the tactile switches (all seem fine.) I also replaced the internal CMOS battery. I was under the impression that MKI 800s didn't have this, so the main board may have been replaced by someone along the line.
> 
> Anyway, has anyone had a problem like this and could help me out? It is potentially one of the ICs, but I have no idea how to test them.
> 
> Thanks,
> 
> Christian
>

>
> Since the switch checked out OK, you would have to look further into the electronics that runs the scanning of the switches.
> 
> What you should do is start from the bottom note on the keyboard and work your way up through all of the keys, normals and accidentals. Take note of which keys do NOT cause the display to count up (the right hand displays should increment by 1 each time to play a note).
> 
> If some of the notes on the keyboard do NOT cause the display to increment then we can check the schematic and see if we can work out which chips or DTC's or diodes or other things might be broken.
> 
> Mike
> 
> 
> 
> 
> ________________________________
>  From: cc0919ship 
> To: korgpolyex@yahoogroups.com 
> Sent: Wednesday, January 23, 2013 8:36 PM
> Subject: [korgpolyex] Re: Frozen Poly 800
>  
> 
> Â  
> Anyone else have any ideas? I really don't want to trash this synth if it is something simple, was really looking forward to using it :(
> 
> --- In korgpolyex@yahoogroups.com, "cc0919ship"  wrote:
> >
> > Hello all,
> > 
> > I'm wondering if you can help me out. I recently acquired a broken Poly 800 (original, not MKII.) It powers up, but immediately after powering up, the screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do not make noise. If I turn up the volume the whole way, I can hear the filter sweeping up and down. Here's where it gets interesting - I plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard, the 800 makes static noises, and the last value on the screen increments by one.
> > 
> > I opened it up, checked the tactile switches (all seem fine.) I also replaced the internal CMOS battery. I was under the impression that MKI 800s didn't have this, so the main board may have been replaced by someone along the line.
> > 
> > Anyway, has anyone had a problem like this and could help me out? It is potentially one of the ICs, but I have no idea how to test them.
> > 
> > Thanks,
> > 
> > Christian
> >
>

>
> Was the battery in a battery holder, or did the battery have tabs attached to it that were soldered to the circuit board?(I'm guessing it was in a battery holder if you were able to change it)
> 
> Did you buy it not working, how many volts was the original battery, did it need changing?
> Is everything the same as before you changed the battery?
>

>
> When you first turn the Poly-800 on, with sequencer disabled, the display
> should say 11 .P (only two sets of digits). The only time you should see
> three sets of digits which increment when you press a key is if the
> sequencer is enabled AND the Start button has been pressed. Do you see any
> change in the display if you press the Prog/Para button a couple of times?
> Do you see any change in the display if you move the Tape switch between
> Disable/Enable? It should say 7APE when it is enabled.
> 
> Don B.
> 
>   _____  
> 
> From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> Behalf Of cc0919ship
> Sent: Wednesday, January 23, 2013 11:20 PM
> To: korgpolyex@yahoogroups.com
> Subject: [korgpolyex] Re: Frozen Poly 800
> 
>  
> 
>   
> 
> 
> Hey Michael,
> 
> Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> every key (including accidentals) incremented the value by 1.
> 
> --- In korgpolyex@yahoogroups.com  ,
> Michael Hawkins wrote:
> >
> > Since the switch checked out OK, you would have to look further into the
> electronics that runs the scanning of the switches.
> > 
> > What you should do is start from the bottom note on the keyboard and work
> your way up through all of the keys, normals and accidentals. Take note of
> which keys do NOT cause the display to count up (the right hand displays
> should increment by 1 each time to play a note).
> > 
> > If some of the notes on the keyboard do NOT cause the display to increment
> then we can check the schematic and see if we can work out which chips or
> DTC's or diodes or other things might be broken.
> > 
> > Mike
> > 
> > 
> > 
> > 
> > ________________________________
> > From: cc0919ship 
> > To: korgpolyex@yahoogroups.com   
> > Sent: Wednesday, January 23, 2013 8:36 PM
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> > 
> > Â  
> > Anyone else have any ideas? I really don't want to trash this synth if it
> is something simple, was really looking forward to using it :(
> > 
> > --- In korgpolyex@yahoogroups.com  ,
> "cc0919ship" wrote:
> > >
> > > Hello all,
> > > 
> > > I'm wondering if you can help me out. I recently acquired a broken Poly
> 800 (original, not MKII.) It powers up, but immediately after powering up,
> the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> keys do not make noise. If I turn up the volume the whole way, I can hear
> the filter sweeping up and down. Here's where it gets interesting - I
> plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> the 800 makes static noises, and the last value on the screen increments by
> one.
> > > 
> > > I opened it up, checked the tactile switches (all seem fine.) I also
> replaced the internal CMOS battery. I was under the impression that MKI 800s
> didn't have this, so the main board may have been replaced by someone along
> the line.
> > > 
> > > Anyway, has anyone had a problem like this and could help me out? It is
> potentially one of the ICs, but I have no idea how to test them.
> > > 
> > > Thanks,
> > > 
> > > Christian
> > >
> >
>

>
> When you first turn the Poly-800 on, with sequencer disabled, the display
> should say 11 .P (only two sets of digits). The only time you should see
> three sets of digits which increment when you press a key is if the
> sequencer is enabled AND the Start button has been pressed. Do you see any
> change in the display if you press the Prog/Para button a couple of times?
> Do you see any change in the display if you move the Tape switch between
> Disable/Enable? It should say 7APE when it is enabled.
> 
> Don B.
> 
>   _____ 
> 
> From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> Behalf Of cc0919ship
> Sent: Wednesday, January 23, 2013 11:20 PM
> To: korgpolyex@yahoogroups.com
> Subject: [korgpolyex] Re: Frozen Poly 800
> 
> 
> 
> 
> 
> 
> Hey Michael,
> 
> Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> every key (including accidentals) incremented the value by 1.
> 
> --- In korgpolyex@yahoogroups.com ,
> Michael Hawkins wrote:
> >
> > Since the switch checked out OK, you would have to look further into the
> electronics that runs the scanning of the switches.
> > 
> > What you should do is start from the bottom note on the keyboard and work
> your way up through all of the keys, normals and accidentals. Take note of
> which keys do NOT cause the display to count up (the right hand displays
> should increment by 1 each time to play a note).
> > 
> > If some of the notes on the keyboard do NOT cause the display to increment
> then we can check the schematic and see if we can work out which chips or
> DTC's or diodes or other things might be broken.
> > 
> > Mike
> > 
> > 
> > 
> > 
> > ________________________________
> > From: cc0919ship 
> > To: korgpolyex@yahoogroups.com 
> > Sent: Wednesday, January 23, 2013 8:36 PM
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> > 
> > Â 
> > Anyone else have any ideas? I really don't want to trash this synth if it
> is something simple, was really looking forward to using it :(
> > 
> > --- In korgpolyex@yahoogroups.com ,
> "cc0919ship" wrote:
> > >
> > > Hello all,
> > > 
> > > I'm wondering if you can help me out. I recently acquired a broken Poly
> 800 (original, not MKII.) It powers up, but immediately after powering up,
> the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> keys do not make noise. If I turn up the volume the whole way, I can hear
> the filter sweeping up and down. Here's where it gets interesting - I
> plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> the 800 makes static noises, and the last value on the screen increments by
> one.
> > > 
> > > I opened it up, checked the tactile switches (all seem fine.) I also
> replaced the internal CMOS battery. I was under the impression that MKI 800s
> didn't have this, so the main board may have been replaced by someone along
> the line.
> > > 
> > > Anyway, has anyone had a problem like this and could help me out? It is
> potentially one of the ICs, but I have no idea how to test them.
> > > 
> > > Thanks,
> > > 
> > > Christian
> > >
> >
>

>
> Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> 
> Then, do you have a multimeter and soldering iron etc?
> 
> Mike
> 
> 
> 
> 
> ________________________________
>  From: cc0919ship 
> To: korgpolyex@yahoogroups.com 
> Sent: Thursday, January 24, 2013 9:14 AM
> Subject: [korgpolyex] Re: Frozen Poly 800
>  
> 
> Â  
> 
> Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> 
> --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> >
> > When you first turn the Poly-800 on, with sequencer disabled, the display
> > should say 11 .P (only two sets of digits). The only time you should see
> > three sets of digits which increment when you press a key is if the
> > sequencer is enabled AND the Start button has been pressed. Do you see any
> > change in the display if you press the Prog/Para button a couple of times?
> > Do you see any change in the display if you move the Tape switch between
> > Disable/Enable? It should say 7APE when it is enabled.
> > 
> > Don B.
> > 
> >   _____ 
> > 
> > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > Behalf Of cc0919ship
> > Sent: Wednesday, January 23, 2013 11:20 PM
> > To: korgpolyex@yahoogroups.com
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> > 
> > 
> > 
> > 
> > 
> > Hey Michael,
> > 
> > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > every key (including accidentals) incremented the value by 1.
> > 
> > --- In korgpolyex@yahoogroups.com ,
> > Michael Hawkins wrote:
> > >
> > > Since the switch checked out OK, you would have to look further into the
> > electronics that runs the scanning of the switches.
> > > 
> > > What you should do is start from the bottom note on the keyboard and work
> > your way up through all of the keys, normals and accidentals. Take note of
> > which keys do NOT cause the display to count up (the right hand displays
> > should increment by 1 each time to play a note).
> > > 
> > > If some of the notes on the keyboard do NOT cause the display to increment
> > then we can check the schematic and see if we can work out which chips or
> > DTC's or diodes or other things might be broken.
> > > 
> > > Mike
> > > 
> > > 
> > > 
> > > 
> > > ________________________________
> > > From: cc0919ship 
> > > To: korgpolyex@yahoogroups.com 
> > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > 
> > > 
> > > Â 
> > > Anyone else have any ideas? I really don't want to trash this synth if it
> > is something simple, was really looking forward to using it :(
> > > 
> > > --- In korgpolyex@yahoogroups.com ,
> > "cc0919ship" wrote:
> > > >
> > > > Hello all,
> > > > 
> > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > keys do not make noise. If I turn up the volume the whole way, I can hear
> > the filter sweeping up and down. Here's where it gets interesting - I
> > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > the 800 makes static noises, and the last value on the screen increments by
> > one.
> > > > 
> > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > didn't have this, so the main board may have been replaced by someone along
> > the line.
> > > > 
> > > > Anyway, has anyone had a problem like this and could help me out? It is
> > potentially one of the ICs, but I have no idea how to test them.
> > > > 
> > > > Thanks,
> > > > 
> > > > Christian
> > > >
> > >
> >
>

>
> Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> 
> Then, do you have a multimeter and soldering iron etc?
> 
> Mike
> 
> 
> 
> 
> ________________________________
>  From: cc0919ship 
> To: korgpolyex@yahoogroups.com 
> Sent: Thursday, January 24, 2013 9:14 AM
> Subject: [korgpolyex] Re: Frozen Poly 800
> 
> 
> Â  
> 
> Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> 
> --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> >
> > When you first turn the Poly-800 on, with sequencer disabled, the display
> > should say 11 .P (only two sets of digits). The only time you should see
> > three sets of digits which increment when you press a key is if the
> > sequencer is enabled AND the Start button has been pressed. Do you see any
> > change in the display if you press the Prog/Para button a couple of times?
> > Do you see any change in the display if you move the Tape switch between
> > Disable/Enable? It should say 7APE when it is enabled.
> > 
> > Don B.
> > 
> >   _____ 
> > 
> > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > Behalf Of cc0919ship
> > Sent: Wednesday, January 23, 2013 11:20 PM
> > To: korgpolyex@yahoogroups.com
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> > 
> > 
> > 
> > 
> > 
> > Hey Michael,
> > 
> > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > every key (including accidentals) incremented the value by 1.
> > 
> > --- In korgpolyex@yahoogroups.com ,
> > Michael Hawkins wrote:
> > >
> > > Since the switch checked out OK, you would have to look further into the
> > electronics that runs the scanning of the switches.
> > > 
> > > What you should do is start from the bottom note on the keyboard and work
> > your way up through all of the keys, normals and accidentals. Take note of
> > which keys do NOT cause the display to count up (the right hand displays
> > should increment by 1 each time to play a note).
> > > 
> > > If some of the notes on the keyboard do NOT cause the display to increment
> > then we can check the schematic and see if we can work out which chips or
> > DTC's or diodes or other things might be broken.
> > > 
> > > Mike
> > > 
> > > 
> > > 
> > > 
> > > ________________________________
> > > From: cc0919ship 
> > > To: korgpolyex@yahoogroups.com 
> > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > 
> > > 
> > > Â 
> > > Anyone else have any ideas? I really don't want to trash this synth if it
> > is something simple, was really looking forward to using it :(
> > > 
> > > --- In korgpolyex@yahoogroups.com ,
> > "cc0919ship" wrote:
> > > >
> > > > Hello all,
> > > > 
> > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > keys do not make noise. If I turn up the volume the whole way, I can hear
> > the filter sweeping up and down. Here's where it gets interesting - I
> > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > the 800 makes static noises, and the last value on the screen increments by
> > one.
> > > > 
> > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > didn't have this, so the main board may have been replaced by someone along
> > the line.
> > > > 
> > > > Anyway, has anyone had a problem like this and could help me out? It is
> > potentially one of the ICs, but I have no idea how to test them.
> > > > 
> > > > Thanks,
> > > > 
> > > > Christian
> > > >
> > >
> >
>

>
> OK, when the Poly goes directly into sequencer edit mode it usually indicates a problem with the chip select "Y4" signal getting through to the 3-11A signal. If you go to the files section and look in the Servicing section for the Poly-800. There's a zip file in there with the schematics. Look at the first schematic and in the upper right hand corner is the section that includes DTC5 and R135. That DTC and the resistor needs to be checked for proper functioning.
> 
> 
> Mike
> 
> 
> 
> ________________________________
>  From: cc0919ship 
> To: korgpolyex@yahoogroups.com 
> Sent: Thursday, January 24, 2013 9:55 AM
> Subject: [korgpolyex] Re: Frozen Poly 800
>  
> 
> Â  
> I have, no signs of corrosion. The guts look in pristine order. I do have both.
> 
> Christian
> 
> --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> >
> > Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> > 
> > Then, do you have a multimeter and soldering iron etc?
> > 
> > Mike
> > 
> > 
> > 
> > 
> > ________________________________
> >  From: cc0919ship 
> > To: korgpolyex@yahoogroups.com 
> > Sent: Thursday, January 24, 2013 9:14 AM
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> > 
> >   
> > 
> > Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> > 
> > --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> > >
> > > When you first turn the Poly-800 on, with sequencer disabled, the display
> > > should say 11 .P (only two sets of digits). The only time you should see
> > > three sets of digits which increment when you press a key is if the
> > > sequencer is enabled AND the Start button has been pressed. Do you see any
> > > change in the display if you press the Prog/Para button a couple of times?
> > > Do you see any change in the display if you move the Tape switch between
> > > Disable/Enable? It should say 7APE when it is enabled.
> > > 
> > > Don B.
> > > 
> > >   _____ 
> > > 
> > > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > > Behalf Of cc0919ship
> > > Sent: Wednesday, January 23, 2013 11:20 PM
> > > To: korgpolyex@yahoogroups.com
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > Hey Michael,
> > > 
> > > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > > every key (including accidentals) incremented the value by 1.
> > > 
> > > --- In korgpolyex@yahoogroups.com ,
> > > Michael Hawkins wrote:
> > > >
> > > > Since the switch checked out OK, you would have to look further into the
> > > electronics that runs the scanning of the switches.
> > > > 
> > > > What you should do is start from the bottom note on the keyboard and work
> > > your way up through all of the keys, normals and accidentals. Take note of
> > > which keys do NOT cause the display to count up (the right hand displays
> > > should increment by 1 each time to play a note).
> > > > 
> > > > If some of the notes on the keyboard do NOT cause the display to increment
> > > then we can check the schematic and see if we can work out which chips or
> > > DTC's or diodes or other things might be broken.
> > > > 
> > > > Mike
> > > > 
> > > > 
> > > > 
> > > > 
> > > > ________________________________
> > > > From: cc0919ship 
> > > > To: korgpolyex@yahoogroups.com 
> > > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > 
> > > > 
> > > > Â 
> > > > Anyone else have any ideas? I really don't want to trash this synth if it
> > > is something simple, was really looking forward to using it :(
> > > > 
> > > > --- In korgpolyex@yahoogroups.com ,
> > > "cc0919ship" wrote:
> > > > >
> > > > > Hello all,
> > > > > 
> > > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > > keys do not make noise. If I turn up the volume the whole way, I can hear
> > > the filter sweeping up and down. Here's where it gets interesting - I
> > > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > > the 800 makes static noises, and the last value on the screen increments by
> > > one.
> > > > > 
> > > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > > didn't have this, so the main board may have been replaced by someone along
> > > the line.
> > > > > 
> > > > > Anyway, has anyone had a problem like this and could help me out? It is
> > > potentially one of the ICs, but I have no idea how to test them.
> > > > > 
> > > > > Thanks,
> > > > > 
> > > > > Christian
> > > > >
> > > >
> > >
> >
>

>
> Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> 
> Then, do you have a multimeter and soldering iron etc?
> 
> Mike
> 
> 
> 
> 
> ________________________________
>  From: cc0919ship 
> To: korgpolyex@yahoogroups.com 
> Sent: Thursday, January 24, 2013 9:14 AM
> Subject: [korgpolyex] Re: Frozen Poly 800
> 
> 
> Â  
> 
> Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> 
> --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> >
> > When you first turn the Poly-800 on, with sequencer disabled, the display
> > should say 11 .P (only two sets of digits). The only time you should see
> > three sets of digits which increment when you press a key is if the
> > sequencer is enabled AND the Start button has been pressed. Do you see any
> > change in the display if you press the Prog/Para button a couple of times?
> > Do you see any change in the display if you move the Tape switch between
> > Disable/Enable? It should say 7APE when it is enabled.
> > 
> > Don B.
> > 
> >   _____ 
> > 
> > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > Behalf Of cc0919ship
> > Sent: Wednesday, January 23, 2013 11:20 PM
> > To: korgpolyex@yahoogroups.com
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> > 
> > 
> > 
> > 
> > 
> > Hey Michael,
> > 
> > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > every key (including accidentals) incremented the value by 1.
> > 
> > --- In korgpolyex@yahoogroups.com ,
> > Michael Hawkins wrote:
> > >
> > > Since the switch checked out OK, you would have to look further into the
> > electronics that runs the scanning of the switches.
> > > 
> > > What you should do is start from the bottom note on the keyboard and work
> > your way up through all of the keys, normals and accidentals. Take note of
> > which keys do NOT cause the display to count up (the right hand displays
> > should increment by 1 each time to play a note).
> > > 
> > > If some of the notes on the keyboard do NOT cause the display to increment
> > then we can check the schematic and see if we can work out which chips or
> > DTC's or diodes or other things might be broken.
> > > 
> > > Mike
> > > 
> > > 
> > > 
> > > 
> > > ________________________________
> > > From: cc0919ship 
> > > To: korgpolyex@yahoogroups.com 
> > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > 
> > > 
> > > Â 
> > > Anyone else have any ideas? I really don't want to trash this synth if it
> > is something simple, was really looking forward to using it :(
> > > 
> > > --- In korgpolyex@yahoogroups.com ,
> > "cc0919ship" wrote:
> > > >
> > > > Hello all,
> > > > 
> > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > keys do not make noise. If I turn up the volume the whole way, I can hear
> > the filter sweeping up and down. Here's where it gets interesting - I
> > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > the 800 makes static noises, and the last value on the screen increments by
> > one.
> > > > 
> > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > didn't have this, so the main board may have been replaced by someone along
> > the line.
> > > > 
> > > > Anyway, has anyone had a problem like this and could help me out? It is
> > potentially one of the ICs, but I have no idea how to test them.
> > > > 
> > > > Thanks,
> > > > 
> > > > Christian
> > > >
> > >
> >
>

>
> Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> 
> Then, do you have a multimeter and soldering iron etc?
> 
> Mike
> 
> 
> 
> 
> ________________________________
> From: cc0919ship 
> To: korgpolyex@yahoogroups.com 
> Sent: Thursday, January 24, 2013 9:14 AM
> Subject: [korgpolyex] Re: Frozen Poly 800
> 
> 
> Â  
> 
> Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> 
> --- In korgpolyex@yahoogroups.com, "backshall1" wrote:
> >
> > When you first turn the Poly-800 on, with sequencer disabled, the display
> > should say 11 .P (only two sets of digits). The only time you should see
> > three sets of digits which increment when you press a key is if the
> > sequencer is enabled AND the Start button has been pressed. Do you see any
> > change in the display if you press the Prog/Para button a couple of times?
> > Do you see any change in the display if you move the Tape switch between
> > Disable/Enable? It should say 7APE when it is enabled.
> > 
> > Don B.
> > 
> > _____ 
> > 
> > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > Behalf Of cc0919ship
> > Sent: Wednesday, January 23, 2013 11:20 PM
> > To: korgpolyex@yahoogroups.com
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> > 
> > 
> > 
> > 
> > 
> > Hey Michael,
> > 
> > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > every key (including accidentals) incremented the value by 1.
> > 
> > --- In korgpolyex@yahoogroups.com ,
> > Michael Hawkins wrote:
> > >
> > > Since the switch checked out OK, you would have to look further into the
> > electronics that runs the scanning of the switches.
> > > 
> > > What you should do is start from the bottom note on the keyboard and work
> > your way up through all of the keys, normals and accidentals. Take note of
> > which keys do NOT cause the display to count up (the right hand displays
> > should increment by 1 each time to play a note).
> > > 
> > > If some of the notes on the keyboard do NOT cause the display to increment
> > then we can check the schematic and see if we can work out which chips or
> > DTC's or diodes or other things might be broken.
> > > 
> > > Mike
> > > 
> > > 
> > > 
> > > 
> > > ________________________________
> > > From: cc0919ship 
> > > To: korgpolyex@yahoogroups.com 
> > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > 
> > > 
> > > Â 
> > > Anyone else have any ideas? I really don't want to trash this synth if it
> > is something simple, was really looking forward to using it :(
> > > 
> > > --- In korgpolyex@yahoogroups.com ,
> > "cc0919ship" wrote:
> > > >
> > > > Hello all,
> > > > 
> > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > keys do not make noise. If I turn up the volume the whole way, I can hear
> > the filter sweeping up and down. Here's where it gets interesting - I
> > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > the 800 makes static noises, and the last value on the screen increments by
> > one.
> > > > 
> > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > didn't have this, so the main board may have been replaced by someone along
> > the line.
> > > > 
> > > > Anyway, has anyone had a problem like this and could help me out? It is
> > potentially one of the ICs, but I have no idea how to test them.
> > > > 
> > > > Thanks,
> > > > 
> > > > Christian
> > > >
> > >
> >
>

>
> OK, when the Poly goes directly into sequencer edit mode it usually indicates a problem with the chip select "Y4" signal getting through to the 3-11A signal. If you go to the files section and look in the Servicing section for the Poly-800. There's a zip file in there with the schematics. Look at the first schematic and in the upper right hand corner is the section that includes DTC5 and R135. That DTC and the resistor needs to be checked for proper functioning.
> 
> 
> Mike
> 
> 
> 
> ________________________________
>  From: cc0919ship 
> To: korgpolyex@yahoogroups.com 
> Sent: Thursday, January 24, 2013 9:55 AM
> Subject: [korgpolyex] Re: Frozen Poly 800
>  
> 
> Â  
> I have, no signs of corrosion. The guts look in pristine order. I do have both.
> 
> Christian
> 
> --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> >
> > Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> > 
> > Then, do you have a multimeter and soldering iron etc?
> > 
> > Mike
> > 
> > 
> > 
> > 
> > ________________________________
> >  From: cc0919ship 
> > To: korgpolyex@yahoogroups.com 
> > Sent: Thursday, January 24, 2013 9:14 AM
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> > 
> >   
> > 
> > Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> > 
> > --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> > >
> > > When you first turn the Poly-800 on, with sequencer disabled, the display
> > > should say 11 .P (only two sets of digits). The only time you should see
> > > three sets of digits which increment when you press a key is if the
> > > sequencer is enabled AND the Start button has been pressed. Do you see any
> > > change in the display if you press the Prog/Para button a couple of times?
> > > Do you see any change in the display if you move the Tape switch between
> > > Disable/Enable? It should say 7APE when it is enabled.
> > > 
> > > Don B.
> > > 
> > >   _____ 
> > > 
> > > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > > Behalf Of cc0919ship
> > > Sent: Wednesday, January 23, 2013 11:20 PM
> > > To: korgpolyex@yahoogroups.com
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > Hey Michael,
> > > 
> > > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > > every key (including accidentals) incremented the value by 1.
> > > 
> > > --- In korgpolyex@yahoogroups.com ,
> > > Michael Hawkins wrote:
> > > >
> > > > Since the switch checked out OK, you would have to look further into the
> > > electronics that runs the scanning of the switches.
> > > > 
> > > > What you should do is start from the bottom note on the keyboard and work
> > > your way up through all of the keys, normals and accidentals. Take note of
> > > which keys do NOT cause the display to count up (the right hand displays
> > > should increment by 1 each time to play a note).
> > > > 
> > > > If some of the notes on the keyboard do NOT cause the display to increment
> > > then we can check the schematic and see if we can work out which chips or
> > > DTC's or diodes or other things might be broken.
> > > > 
> > > > Mike
> > > > 
> > > > 
> > > > 
> > > > 
> > > > ________________________________
> > > > From: cc0919ship 
> > > > To: korgpolyex@yahoogroups.com 
> > > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > 
> > > > 
> > > > Â 
> > > > Anyone else have any ideas? I really don't want to trash this synth if it
> > > is something simple, was really looking forward to using it :(
> > > > 
> > > > --- In korgpolyex@yahoogroups.com ,
> > > "cc0919ship" wrote:
> > > > >
> > > > > Hello all,
> > > > > 
> > > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > > keys do not make noise. If I turn up the volume the whole way, I can hear
> > > the filter sweeping up and down. Here's where it gets interesting - I
> > > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > > the 800 makes static noises, and the last value on the screen increments by
> > > one.
> > > > > 
> > > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > > didn't have this, so the main board may have been replaced by someone along
> > > the line.
> > > > > 
> > > > > Anyway, has anyone had a problem like this and could help me out? It is
> > > potentially one of the ICs, but I have no idea how to test them.
> > > > > 
> > > > > Thanks,
> > > > > 
> > > > > Christian
> > > > >
> > > >
> > >
> >
>

>
> Compare the resistances across the three legs of DTC5 with two or three of the other DTC's. If there's a significant difference then you probably have found the cuplrit.
> 
> however, before you assume it is the DTC itself. Resolder the resistor and DTC legs. I've seen quite a few cold solder joints over the years. Resolder and see if you get lucky.
> 
> Mike
> 
> 
> 
> 
> ________________________________
>  From: cc0919ship 
> To: korgpolyex@yahoogroups.com 
> Sent: Thursday, January 24, 2013 9:55 AM
> Subject: [korgpolyex] Re: Frozen Poly 800
>  
> 
> Â  
> I have, no signs of corrosion. The guts look in pristine order. I do have both.
> 
> Christian
> 
> --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> >
> > Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> > 
> > Then, do you have a multimeter and soldering iron etc?
> > 
> > Mike
> > 
> > 
> > 
> > 
> > ________________________________
> >  From: cc0919ship 
> > To: korgpolyex@yahoogroups.com 
> > Sent: Thursday, January 24, 2013 9:14 AM
> > Subject: [korgpolyex] Re: Frozen Poly 800
> > 
> > 
> >   
> > 
> > Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> > 
> > --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> > >
> > > When you first turn the Poly-800 on, with sequencer disabled, the display
> > > should say 11 .P (only two sets of digits). The only time you should see
> > > three sets of digits which increment when you press a key is if the
> > > sequencer is enabled AND the Start button has been pressed. Do you see any
> > > change in the display if you press the Prog/Para button a couple of times?
> > > Do you see any change in the display if you move the Tape switch between
> > > Disable/Enable? It should say 7APE when it is enabled.
> > > 
> > > Don B.
> > > 
> > >   _____ 
> > > 
> > > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > > Behalf Of cc0919ship
> > > Sent: Wednesday, January 23, 2013 11:20 PM
> > > To: korgpolyex@yahoogroups.com
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > Hey Michael,
> > > 
> > > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > > every key (including accidentals) incremented the value by 1.
> > > 
> > > --- In korgpolyex@yahoogroups.com ,
> > > Michael Hawkins wrote:
> > > >
> > > > Since the switch checked out OK, you would have to look further into the
> > > electronics that runs the scanning of the switches.
> > > > 
> > > > What you should do is start from the bottom note on the keyboard and work
> > > your way up through all of the keys, normals and accidentals. Take note of
> > > which keys do NOT cause the display to count up (the right hand displays
> > > should increment by 1 each time to play a note).
> > > > 
> > > > If some of the notes on the keyboard do NOT cause the display to increment
> > > then we can check the schematic and see if we can work out which chips or
> > > DTC's or diodes or other things might be broken.
> > > > 
> > > > Mike
> > > > 
> > > > 
> > > > 
> > > > 
> > > > ________________________________
> > > > From: cc0919ship 
> > > > To: korgpolyex@yahoogroups.com 
> > > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > 
> > > > 
> > > > Â 
> > > > Anyone else have any ideas? I really don't want to trash this synth if it
> > > is something simple, was really looking forward to using it :(
> > > > 
> > > > --- In korgpolyex@yahoogroups.com ,
> > > "cc0919ship" wrote:
> > > > >
> > > > > Hello all,
> > > > > 
> > > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > > keys do not make noise. If I turn up the volume the whole way, I can hear
> > > the filter sweeping up and down. Here's where it gets interesting - I
> > > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > > the 800 makes static noises, and the last value on the screen increments by
> > > one.
> > > > > 
> > > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > > didn't have this, so the main board may have been replaced by someone along
> > > the line.
> > > > > 
> > > > > Anyway, has anyone had a problem like this and could help me out? It is
> > > potentially one of the ICs, but I have no idea how to test them.
> > > > > 
> > > > > Thanks,
> > > > > 
> > > > > Christian
> > > > >
> > > >
> > >
> >
>

>
> Mike,
> 
> Just tested DTC5 and it is significantly higher (and shows resistance both ways) so it looks as though I may have found the culprit! I'm going to resolder it first as suggested.
> 
> Christian
> 
> --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> >
> > Compare the resistances across the three legs of DTC5 with two or three of the other DTC's. If there's a significant difference then you probably have found the cuplrit.
> > 
> > however, before you assume it is the DTC itself. Resolder the resistor and DTC legs. I've seen quite a few cold solder joints over the years. Resolder and see if you get lucky.
> > 
> > Mike
> > 
> > 
> > 
> > 
> > ________________________________
> >  From: cc0919ship 
> > To: korgpolyex@yahoogroups.com 
> > Sent: Thursday, January 24, 2013 9:55 AM
> > Subject: [korgpolyex] Re: Frozen Poly 800
> >  
> > 
> > Â  
> > I have, no signs of corrosion. The guts look in pristine order. I do have both.
> > 
> > Christian
> > 
> > --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> > >
> > > Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> > > 
> > > Then, do you have a multimeter and soldering iron etc?
> > > 
> > > Mike
> > > 
> > > 
> > > 
> > > 
> > > ________________________________
> > >  From: cc0919ship 
> > > To: korgpolyex@yahoogroups.com 
> > > Sent: Thursday, January 24, 2013 9:14 AM
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > 
> > > 
> > >   
> > > 
> > > Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> > > 
> > > --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> > > >
> > > > When you first turn the Poly-800 on, with sequencer disabled, the display
> > > > should say 11 .P (only two sets of digits). The only time you should see
> > > > three sets of digits which increment when you press a key is if the
> > > > sequencer is enabled AND the Start button has been pressed. Do you see any
> > > > change in the display if you press the Prog/Para button a couple of times?
> > > > Do you see any change in the display if you move the Tape switch between
> > > > Disable/Enable? It should say 7APE when it is enabled.
> > > > 
> > > > Don B.
> > > > 
> > > >   _____ 
> > > > 
> > > > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > > > Behalf Of cc0919ship
> > > > Sent: Wednesday, January 23, 2013 11:20 PM
> > > > To: korgpolyex@yahoogroups.com
> > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > Hey Michael,
> > > > 
> > > > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > > > every key (including accidentals) incremented the value by 1.
> > > > 
> > > > --- In korgpolyex@yahoogroups.com ,
> > > > Michael Hawkins wrote:
> > > > >
> > > > > Since the switch checked out OK, you would have to look further into the
> > > > electronics that runs the scanning of the switches.
> > > > > 
> > > > > What you should do is start from the bottom note on the keyboard and work
> > > > your way up through all of the keys, normals and accidentals. Take note of
> > > > which keys do NOT cause the display to count up (the right hand displays
> > > > should increment by 1 each time to play a note).
> > > > > 
> > > > > If some of the notes on the keyboard do NOT cause the display to increment
> > > > then we can check the schematic and see if we can work out which chips or
> > > > DTC's or diodes or other things might be broken.
> > > > > 
> > > > > Mike
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > > ________________________________
> > > > > From: cc0919ship 
> > > > > To: korgpolyex@yahoogroups.com 
> > > > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > > 
> > > > > 
> > > > > Â 
> > > > > Anyone else have any ideas? I really don't want to trash this synth if it
> > > > is something simple, was really looking forward to using it :(
> > > > > 
> > > > > --- In korgpolyex@yahoogroups.com ,
> > > > "cc0919ship" wrote:
> > > > > >
> > > > > > Hello all,
> > > > > > 
> > > > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > > > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > > > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > > > keys do not make noise. If I turn up the volume the whole way, I can hear
> > > > the filter sweeping up and down. Here's where it gets interesting - I
> > > > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > > > the 800 makes static noises, and the last value on the screen increments by
> > > > one.
> > > > > > 
> > > > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > > > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > > > didn't have this, so the main board may have been replaced by someone along
> > > > the line.
> > > > > > 
> > > > > > Anyway, has anyone had a problem like this and could help me out? It is
> > > > potentially one of the ICs, but I have no idea how to test them.
> > > > > > 
> > > > > > Thanks,
> > > > > > 
> > > > > > Christian
> > > > > >
> > > > >
> > > >
> > >
> >
>

>
> Mike,
> 
> Just tested DTC5 and it is significantly higher (and shows resistance both ways) so it looks as though I may have found the culprit! I'm going to resolder it first as suggested.
> 
> Christian
> 
> --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> >
> > Compare the resistances across the three legs of DTC5 with two or three of the other DTC's. If there's a significant difference then you probably have found the cuplrit.
> > 
> > however, before you assume it is the DTC itself. Resolder the resistor and DTC legs. I've seen quite a few cold solder joints over the years. Resolder and see if you get lucky.
> > 
> > Mike
> > 
> > 
> > 
> > 
> > ________________________________
> >  From: cc0919ship 
> > To: korgpolyex@yahoogroups.com 
> > Sent: Thursday, January 24, 2013 9:55 AM
> > Subject: [korgpolyex] Re: Frozen Poly 800
> >  
> > 
> > Â  
> > I have, no signs of corrosion. The guts look in pristine order. I do have both.
> > 
> > Christian
> > 
> > --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> > >
> > > Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> > > 
> > > Then, do you have a multimeter and soldering iron etc?
> > > 
> > > Mike
> > > 
> > > 
> > > 
> > > 
> > > ________________________________
> > >  From: cc0919ship 
> > > To: korgpolyex@yahoogroups.com 
> > > Sent: Thursday, January 24, 2013 9:14 AM
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > 
> > > 
> > >   
> > > 
> > > Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> > > 
> > > --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> > > >
> > > > When you first turn the Poly-800 on, with sequencer disabled, the display
> > > > should say 11 .P (only two sets of digits). The only time you should see
> > > > three sets of digits which increment when you press a key is if the
> > > > sequencer is enabled AND the Start button has been pressed. Do you see any
> > > > change in the display if you press the Prog/Para button a couple of times?
> > > > Do you see any change in the display if you move the Tape switch between
> > > > Disable/Enable? It should say 7APE when it is enabled.
> > > > 
> > > > Don B.
> > > > 
> > > >   _____ 
> > > > 
> > > > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > > > Behalf Of cc0919ship
> > > > Sent: Wednesday, January 23, 2013 11:20 PM
> > > > To: korgpolyex@yahoogroups.com
> > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > Hey Michael,
> > > > 
> > > > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > > > every key (including accidentals) incremented the value by 1.
> > > > 
> > > > --- In korgpolyex@yahoogroups.com ,
> > > > Michael Hawkins wrote:
> > > > >
> > > > > Since the switch checked out OK, you would have to look further into the
> > > > electronics that runs the scanning of the switches.
> > > > > 
> > > > > What you should do is start from the bottom note on the keyboard and work
> > > > your way up through all of the keys, normals and accidentals. Take note of
> > > > which keys do NOT cause the display to count up (the right hand displays
> > > > should increment by 1 each time to play a note).
> > > > > 
> > > > > If some of the notes on the keyboard do NOT cause the display to increment
> > > > then we can check the schematic and see if we can work out which chips or
> > > > DTC's or diodes or other things might be broken.
> > > > > 
> > > > > Mike
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > > ________________________________
> > > > > From: cc0919ship 
> > > > > To: korgpolyex@yahoogroups.com 
> > > > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > > 
> > > > > 
> > > > > Â 
> > > > > Anyone else have any ideas? I really don't want to trash this synth if it
> > > > is something simple, was really looking forward to using it :(
> > > > > 
> > > > > --- In korgpolyex@yahoogroups.com ,
> > > > "cc0919ship" wrote:
> > > > > >
> > > > > > Hello all,
> > > > > > 
> > > > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > > > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > > > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > > > keys do not make noise. If I turn up the volume the whole way, I can hear
> > > > the filter sweeping up and down. Here's where it gets interesting - I
> > > > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > > > the 800 makes static noises, and the last value on the screen increments by
> > > > one.
> > > > > > 
> > > > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > > > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > > > didn't have this, so the main board may have been replaced by someone along
> > > > the line.
> > > > > > 
> > > > > > Anyway, has anyone had a problem like this and could help me out? It is
> > > > potentially one of the ICs, but I have no idea how to test them.
> > > > > > 
> > > > > > Thanks,
> > > > > > 
> > > > > > Christian
> > > > > >
> > > > >
> > > >
> > >
> >
>

>
> 
> I may have spoken too soon, in my haste it looks like I misread...now that it is out, it seems fine. Currently tracking down R135.
> --- In korgpolyex@yahoogroups.com, "cc0919ship"  wrote:
> >
> > Mike,
> > 
> > Just tested DTC5 and it is significantly higher (and shows resistance both ways) so it looks as though I may have found the culprit! I'm going to resolder it first as suggested.
> > 
> > Christian
> > 
> > --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> > >
> > > Compare the resistances across the three legs of DTC5 with two or three of the other DTC's. If there's a significant difference then you probably have found the cuplrit.
> > > 
> > > however, before you assume it is the DTC itself. Resolder the resistor and DTC legs. I've seen quite a few cold solder joints over the years. Resolder and see if you get lucky.
> > > 
> > > Mike
> > > 
> > > 
> > > 
> > > 
> > > ________________________________
> > >  From: cc0919ship 
> > > To: korgpolyex@yahoogroups.com 
> > > Sent: Thursday, January 24, 2013 9:55 AM
> > > Subject: [korgpolyex] Re: Frozen Poly 800
> > >  
> > > 
> > > Â  
> > > I have, no signs of corrosion. The guts look in pristine order. I do have both.
> > > 
> > > Christian
> > > 
> > > --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> > > >
> > > > Have you opened up the Poly and had a look to see if there is any sign of brown sludge that might have come from old batteries in the battery compartment? Let's exclude that first.
> > > > 
> > > > Then, do you have a multimeter and soldering iron etc?
> > > > 
> > > > Mike
> > > > 
> > > > 
> > > > 
> > > > 
> > > > ________________________________
> > > >  From: cc0919ship 
> > > > To: korgpolyex@yahoogroups.com 
> > > > Sent: Thursday, January 24, 2013 9:14 AM
> > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > 
> > > > 
> > > >   
> > > > 
> > > > Hm...Don, no matter what switches are enabled or disabled, and no matter what buttons on the front panel are pressed (or how many times) the display stays at 1.8 50 01 (unless I use the MIDI keyboard.) I'll try again with the Tape switch, but I'm almost positive that any change in switches doesn't yield any sort of result. I've definitely never seen it say 11 .P, no matter what I did (although I think that once I hit keys on the MIDI keyboard enough, it did change to 1.8 .P once.
> > > > 
> > > > --- In korgpolyex@yahoogroups.com, "backshall1"  wrote:
> > > > >
> > > > > When you first turn the Poly-800 on, with sequencer disabled, the display
> > > > > should say 11 .P (only two sets of digits). The only time you should see
> > > > > three sets of digits which increment when you press a key is if the
> > > > > sequencer is enabled AND the Start button has been pressed. Do you see any
> > > > > change in the display if you press the Prog/Para button a couple of times?
> > > > > Do you see any change in the display if you move the Tape switch between
> > > > > Disable/Enable? It should say 7APE when it is enabled.
> > > > > 
> > > > > Don B.
> > > > > 
> > > > >   _____ 
> > > > > 
> > > > > From: korgpolyex@yahoogroups.com [mailto:korgpolyex@yahoogroups.com] On
> > > > > Behalf Of cc0919ship
> > > > > Sent: Wednesday, January 23, 2013 11:20 PM
> > > > > To: korgpolyex@yahoogroups.com
> > > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > > Hey Michael,
> > > > > 
> > > > > Thanks so much for the response! I plugged in my 88 key MIDI controller, and
> > > > > every key (including accidentals) incremented the value by 1.
> > > > > 
> > > > > --- In korgpolyex@yahoogroups.com ,
> > > > > Michael Hawkins wrote:
> > > > > >
> > > > > > Since the switch checked out OK, you would have to look further into the
> > > > > electronics that runs the scanning of the switches.
> > > > > > 
> > > > > > What you should do is start from the bottom note on the keyboard and work
> > > > > your way up through all of the keys, normals and accidentals. Take note of
> > > > > which keys do NOT cause the display to count up (the right hand displays
> > > > > should increment by 1 each time to play a note).
> > > > > > 
> > > > > > If some of the notes on the keyboard do NOT cause the display to increment
> > > > > then we can check the schematic and see if we can work out which chips or
> > > > > DTC's or diodes or other things might be broken.
> > > > > > 
> > > > > > Mike
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > ________________________________
> > > > > > From: cc0919ship 
> > > > > > To: korgpolyex@yahoogroups.com 
> > > > > > Sent: Wednesday, January 23, 2013 8:36 PM
> > > > > > Subject: [korgpolyex] Re: Frozen Poly 800
> > > > > > 
> > > > > > 
> > > > > > Â 
> > > > > > Anyone else have any ideas? I really don't want to trash this synth if it
> > > > > is something simple, was really looking forward to using it :(
> > > > > > 
> > > > > > --- In korgpolyex@yahoogroups.com ,
> > > > > "cc0919ship" wrote:
> > > > > > >
> > > > > > > Hello all,
> > > > > > > 
> > > > > > > I'm wondering if you can help me out. I recently acquired a broken Poly
> > > > > 800 (original, not MKII.) It powers up, but immediately after powering up,
> > > > > the screen reads "1.8 50 01." Buttons on the front panel do nothing, and
> > > > > keys do not make noise. If I turn up the volume the whole way, I can hear
> > > > > the filter sweeping up and down. Here's where it gets interesting - I
> > > > > plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard,
> > > > > the 800 makes static noises, and the last value on the screen increments by
> > > > > one.
> > > > > > > 
> > > > > > > I opened it up, checked the tactile switches (all seem fine.) I also
> > > > > replaced the internal CMOS battery. I was under the impression that MKI 800s
> > > > > didn't have this, so the main board may have been replaced by someone along
> > > > > the line.
> > > > > > > 
> > > > > > > Anyway, has anyone had a problem like this and could help me out? It is
> > > > > potentially one of the ICs, but I have no idea how to test them.
> > > > > > > 
> > > > > > > Thanks,
> > > > > > > 
> > > > > > > Christian
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>

>
> Hello all,
> 
> I'm wondering if you can help me out. I recently acquired a broken Poly 800 (original, not MKII.) It powers up, but immediately after powering up, the screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do not make noise. If I turn up the volume the whole way, I can hear the filter sweeping up and down. Here's where it gets interesting - I plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard, the 800 makes static noises, and the last value on the screen increments by one.
> 
> I opened it up, checked the tactile switches (all seem fine.) I also replaced the internal CMOS battery. I was under the impression that MKI 800s didn't have this, so the main board may have been replaced by someone along the line.
> 
> Anyway, has anyone had a problem like this and could help me out? It is potentially one of the ICs, but I have no idea how to test them.
> 
> Thanks,
> 
> Christian
>

>
> Hello all,
> 
> I'm wondering if you can help me out. I recently acquired a broken Poly 800 (original, not MKII.) It powers up, but immediately after powering up, the screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do not make noise. If I turn up the volume the whole way, I can hear the filter sweeping up and down. Here's where it gets interesting - I plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard, the 800 makes static noises, and the last value on the screen increments by one.
> 
> I opened it up, checked the tactile switches (all seem fine.) I also replaced the internal CMOS battery. I was under the impression that MKI 800s didn't have this, so the main board may have been replaced by someone along the line.
> 
> Anyway, has anyone had a problem like this and could help me out? It is potentially one of the ICs, but I have no idea how to test them.
> 
> Thanks,
> 
> Christian
>

>
> Hello all,
> 
> I'm wondering if you can help me out. I recently acquired a broken Poly 800 (original, not MKII.) It powers up, but immediately after powering up, the screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do not make noise. If I turn up the volume the whole way, I can hear the filter sweeping up and down. Here's where it gets interesting - I plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard, the 800 makes static noises, and the last value on the screen increments by one.
> 
> I opened it up, checked the tactile switches (all seem fine.) I also replaced the internal CMOS battery. I was under the impression that MKI 800s didn't have this, so the main board may have been replaced by someone along the line.
> 
> Anyway, has anyone had a problem like this and could help me out? It is potentially one of the ICs, but I have no idea how to test them.
> 
> Thanks,
> 
> Christian
>

>
> Hello all,
> 
> I'm wondering if you can help me out. I recently acquired a broken Poly 800 (original, not MKII.) It powers up, but immediately after powering up, the screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do not make noise. If I turn up the volume the whole way, I can hear the filter sweeping up and down. Here's where it gets interesting - I plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard, the 800 makes static noises, and the last value on the screen increments by one.
> 
> I opened it up, checked the tactile switches (all seem fine.) I also replaced the internal CMOS battery. I was under the impression that MKI 800s didn't have this, so the main board may have been replaced by someone along the line.
> 
> Anyway, has anyone had a problem like this and could help me out? It is potentially one of the ICs, but I have no idea how to test them.
> 
> Thanks,
> 
> Christian
>

>
> If swapping the DTC fixes the sequencer enable problem but then stops the "Step Up" from working (difficult to test if you don't have a pedal). Then you need to find a replacement DTC.
> 
> If it doesn't fix the problem then you need to resolder all pins on IC33 and IC34. If that doesn't fix it then replace 74HC240 IC33 first. If that doesn't fix it then replace 74HC138 IC34.
> 
> I've seen the 74HC240 fail a few times. I have not seen the 74HC138 fail.
> 
> 
> Mike
> 
> 
> 
> ________________________________
>  From: Michael Hawkins 
> To: "korgpolyex@yahoogroups.com"  
> Sent: Friday, January 25, 2013 6:59 PM
> Subject: Re: [korgpolyex] Re: Frozen Poly 800
>  
> 
> Â  
> I've seen the DTC's fail both on this forum and in working with some of my customers.
> 
> So swap DTC4 for DTC5. DTC4 is used for the "Step up" jack. So you can swap it and see if you get anywhere.
> 
> DTC stands for digital transistor something or other. They are essentially a transistor with a couple of bias resistors built into one package so that they act like a saturated transistor switch. There are DTC's out there now more commonly known as BRT's.
> 
> http://www.onsemi.com/PowerSolutions/product.do?id=DTC144TM3
> http://www.onsemi.com/PowerSolutions/parametrics.do?id=799
> 
> Mike
> 
> 
> 
> 
> ________________________________
>  From: cc0919ship 
> To: korgpolyex@yahoogroups.com 
> Sent: Thursday, January 24, 2013 10:38 PM
> Subject: [korgpolyex] Re: Frozen Poly 800
>  
> 
> Â  
> Sorry about all the posts, but it might be important to note that the display was the same even with the transistor removed
> 
> --- In korgpolyex@yahoogroups.com, "cc0919ship"  wrote:
> >
> > Hello all,
> > 
> > I'm wondering if you can help me out. I recently acquired a broken Poly 800 (original, not MKII.) It powers up, but immediately after powering up, the screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do not make noise. If I turn up the volume the whole way, I can hear the filter sweeping up and down. Here's where it gets interesting - I plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard, the 800 makes static noises, and the last value on the screen increments by one.
> > 
> > I opened it up, checked the tactile switches (all seem fine.) I also replaced the internal CMOS battery. I was under the impression that MKI 800s didn't have this, so the main board may have been replaced by someone along the line.
> > 
> > Anyway, has anyone had a problem like this and could help me out? It is potentially one of the ICs, but I have no idea how to test them.
> > 
> > Thanks,
> > 
> > Christian
> >
>

>
> Tried everything, no dice...looks like it might be IC33. Ordering one now. Thanks
> 
> --- In korgpolyex@yahoogroups.com, Michael Hawkins  wrote:
> >
> > If swapping the DTC fixes the sequencer enable problem but then stops the "Step Up" from working (difficult to test if you don't have a pedal). Then you need to find a replacement DTC.
> > 
> > If it doesn't fix the problem then you need to resolder all pins on IC33 and IC34. If that doesn't fix it then replace 74HC240 IC33 first. If that doesn't fix it then replace 74HC138 IC34.
> > 
> > I've seen the 74HC240 fail a few times. I have not seen the 74HC138 fail.
> > 
> > 
> > Mike
> > 
> > 
> > 
> > ________________________________
> >  From: Michael Hawkins 
> > To: "korgpolyex@yahoogroups.com"  
> > Sent: Friday, January 25, 2013 6:59 PM
> > Subject: Re: [korgpolyex] Re: Frozen Poly 800
> >  
> > 
> > Â  
> > I've seen the DTC's fail both on this forum and in working with some of my customers.
> > 
> > So swap DTC4 for DTC5. DTC4 is used for the "Step up" jack. So you can swap it and see if you get anywhere.
> > 
> > DTC stands for digital transistor something or other. They are essentially a transistor with a couple of bias resistors built into one package so that they act like a saturated transistor switch. There are DTC's out there now more commonly known as BRT's.
> > 
> > http://www.onsemi.com/PowerSolutions/product.do?id=DTC144TM3
> > http://www.onsemi.com/PowerSolutions/parametrics.do?id=799
> > 
> > Mike
> > 
> > 
> > 
> > 
> > ________________________________
> >  From: cc0919ship 
> > To: korgpolyex@yahoogroups.com 
> > Sent: Thursday, January 24, 2013 10:38 PM
> > Subject: [korgpolyex] Re: Frozen Poly 800
> >  
> > 
> > Â  
> > Sorry about all the posts, but it might be important to note that the display was the same even with the transistor removed
> > 
> > --- In korgpolyex@yahoogroups.com, "cc0919ship"  wrote:
> > >
> > > Hello all,
> > > 
> > > I'm wondering if you can help me out. I recently acquired a broken Poly 800 (original, not MKII.) It powers up, but immediately after powering up, the screen reads "1.8 50 01." Buttons on the front panel do nothing, and keys do not make noise. If I turn up the volume the whole way, I can hear the filter sweeping up and down. Here's where it gets interesting - I plugged in a MIDI keyboard, and when I play notes with the MIDI keyboard, the 800 makes static noises, and the last value on the screen increments by one.
> > > 
> > > I opened it up, checked the tactile switches (all seem fine.) I also replaced the internal CMOS battery. I was under the impression that MKI 800s didn't have this, so the main board may have been replaced by someone along the line.
> > > 
> > > Anyway, has anyone had a problem like this and could help me out? It is potentially one of the ICs, but I have no idea how to test them.
> > > 
> > > Thanks,
> > > 
> > > Christian
> > >
> >
>

>
> On 25/02/13 21:08, silvereletellier wrote:
> > Hey everyone,
> > I'm glad this forum exists!
> > My poly800 just came up with this 1.8 50 01 screen...
> > cc0919ship could you tell me if replacing IC33 solved your problem?
> > I really don't want to sell it for parts... Hopefully it's just a chip that needs changing!
> 
> And you *have* checked the sequencer switch, right?
> 
> -- 
> Gordonjcp MM0YEQ
>

>
> Not yet to be honest. By the sequencer switch do you mean the actual button switch or the electronic around it? I don't really know what is connected to what. 
> Could you help locating the possibly damaged part please?
> 
> Thanks a lot
> Silvere
> 
> --- In korgpolyex@yahoogroups.com, Gordon JC Pearce <gordon@> wrote:
> >
> > On 25/02/13 21:08, silvereletellier wrote:
> > > Hey everyone,
> > > I'm glad this forum exists!
> > > My poly800 just came up with this 1.8 50 01 screen...
> > > cc0919ship could you tell me if replacing IC33 solved your problem?
> > > I really don't want to sell it for parts... Hopefully it's just a chip that needs changing!
> > 
> > And you *have* checked the sequencer switch, right?
> > 
> > -- 
> > Gordonjcp MM0YEQ
> >
>

>
> 
> Hey!
> 
> Sorry for the belated post, been away and haven't been near email...it was relaxing :) I tried replacing IC33 and IC34, didn't do it for me though, so I may end up having to give up :( Hopefully you can get yours sorted out! If you look at some of the earlier replies on this thread these nice people talk about how to test the sequencer switch, as well as the DTCs. The sequencer switch isn't on the front panel, rather it is on the back.
> 
> Christian
> --- In korgpolyex@yahoogroups.com, "silvereletellier" <silvereletellier@> wrote:
> >
> > Not yet to be honest. By the sequencer switch do you mean the actual button switch or the electronic around it? I don't really know what is connected to what. 
> > Could you help locating the possibly damaged part please?
> > 
> > Thanks a lot
> > Silvere
> > 
> > --- In korgpolyex@yahoogroups.com, Gordon JC Pearce <gordon@> wrote:
> > >
> > > On 25/02/13 21:08, silvereletellier wrote:
> > > > Hey everyone,
> > > > I'm glad this forum exists!
> > > > My poly800 just came up with this 1.8 50 01 screen...
> > > > cc0919ship could you tell me if replacing IC33 solved your problem?
> > > > I really don't want to sell it for parts... Hopefully it's just a chip that needs changing!
> > > 
> > > And you *have* checked the sequencer switch, right?
> > > 
> > > -- 
> > > Gordonjcp MM0YEQ
> > >
> >
>