Yamaha CS80

OK - time to yell for help.

Cleaning up a CS-80, and there's no voices sounding when playing a key. Started debugging at the KAS. All power looks good, note values are registering. Nothing appearing on the trigger outputs. Going backwards, the U1 -> U5 are mostly pegged at 8.48v and do not change no matter where on the keyboard I press.

Is this a dead YM26600, or is there something else causing this?

While I'm here, what should the clock input on pin 2 really look like? I'm not really seeing a stable square wave kind of oscillation there.

thanks

Hi ,

Let us know what has been done/restored previously to this particular YAMAHA CS-80 ? Are the original 4000-Series CMOS chips still in there ? Have you started replacing some capacitors, yet ? How long have you had this machine ? Has it ever played (I mean while you have it ) ?

Csaba

On Apr 18, 2010, at 4:46 AM, tmoravan wrote:

> OK - time to yell for help.
>
> Cleaning up a CS-80, and there's no voices sounding when playing a key. Started debugging at the KAS. All power looks good, note values are registering. Nothing appearing on the trigger outputs. Going backwards, the U1 -> U5 are mostly pegged at 8.48v and do not change no matter where on the keyboard I press.
>
> Is this a dead YM26600, or is there something else causing this?
>
> While I'm here, what should the clock input on pin 2 really look like? I'm not really seeing a stable square wave kind of oscillation there.
>
> thanks
>
>



[Non-text portions of this message have been removed]

Good questions.

Power supply has been recapped, new regulators, etc. I replaced the 4000 CMOS ICs on the TKC board. The synth was playing, but I was having weird problems like 1 voice would continue to sound (but I could still trigger new notes). I had been testing various cards trying to solve that problem and discovered a few wires had broken loose from their solder positions.

The last round of testing - I had all the wires correctly soldered (they matched the color and positions in the service manual) and one of the lower boards (KAS, SH, TKC) shifted at some point and blew the 500mA fuses in the PS. I replaced the fuses, checked for obvious shorts (didn't find any), powered up without the large connector (I jumpered the +/- 15 and sense lines as stated in the docs) and checked all power supply voltages. They are all correct. I plugged the large connector back in, pulled the sense jumpers, and powered up. Voltages through the entire synth are correct and stable at all the boards. However, now I get no triggering of voices.

--- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@...> wrote:
>
> Hi ,
>
> Let us know what has been done/restored previously to this particular YAMAHA CS-80 ? Are the original 4000-Series CMOS chips still in there ? Have you started replacing some capacitors, yet ? How long have you had this machine ? Has it ever played (I mean while you have it ) ?
>
> Csaba
>
> On Apr 18, 2010, at 4:46 AM, tmoravan wrote:
>
> > OK - time to yell for help.
> >
> > Cleaning up a CS-80, and there's no voices sounding when playing a key. Started debugging at the KAS. All power looks good, note values are registering. Nothing appearing on the trigger outputs. Going backwards, the U1 -> U5 are mostly pegged at 8.48v and do not change no matter where on the keyboard I press.
> >
> > Is this a dead YM26600, or is there something else causing this?
> >
> > While I'm here, what should the clock input on pin 2 really look like? I'm not really seeing a stable square wave kind of oscillation there.
> >
> > thanks
> >
> >
>
>
>
> [Non-text portions of this message have been removed]
>

Hmm ... continue refreshing the CMOS chips to newer parts and replace all capacitors maybe even the trimm pots for the SH, KAS boards. What about decoupling capacitors on the TKC board . Have you installed them when you replaced all the 4000 -CMOS chips there ?

Should look like this after the repair/restore http://www.oldcrows.net/~oldcrow/synth/yamaha/cs80/CS80TKC3.jpg

On Apr 18, 2010, at 1:40 PM, tmoravan wrote:

> Good questions.
>
> Power supply has been recapped, new regulators, etc. I replaced the 4000 CMOS ICs on the TKC board. The synth was playing, but I was having weird problems like 1 voice would continue to sound (but I could still trigger new notes). I had been testing various cards trying to solve that problem and discovered a few wires had broken loose from their solder positions.
>
> The last round of testing - I had all the wires correctly soldered (they matched the color and positions in the service manual) and one of the lower boards (KAS, SH, TKC) shifted at some point and blew the 500mA fuses in the PS. I replaced the fuses, checked for obvious shorts (didn't find any), powered up without the large connector (I jumpered the +/- 15 and sense lines as stated in the docs) and checked all power supply voltages. They are all correct. I plugged the large connector back in, pulled the sense jumpers, and powered up. Voltages through the entire synth are correct and stable at all the boards. However, now I get no triggering of voices.
>
> --- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@...> wrote:
> >
> > Hi ,
> >
> > Let us know what has been done/restored previously to this particular YAMAHA CS-80 ? Are the original 4000-Series CMOS chips still in there ? Have you started replacing some capacitors, yet ? How long have you had this machine ? Has it ever played (I mean while you have it ) ?
> >
> > Csaba
> >
> > On Apr 18, 2010, at 4:46 AM, tmoravan wrote:
> >
> > > OK - time to yell for help.
> > >
> > > Cleaning up a CS-80, and there's no voices sounding when playing a key. Started debugging at the KAS. All power looks good, note values are registering. Nothing appearing on the trigger outputs. Going backwards, the U1 -> U5 are mostly pegged at 8.48v and do not change no matter where on the keyboard I press.
> > >
> > > Is this a dead YM26600, or is there something else causing this?
> > >
> > > While I'm here, what should the clock input on pin 2 really look like? I'm not really seeing a stable square wave kind of oscillation there.
> > >
> > > thanks
> > >
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>



[Non-text portions of this message have been removed]

Well, I have sound again. Now back to the 'stuck on' note and another with the wrong pitch. I replaced the two 4558's and the 2 4069's on the KAS and now the YM26600 and YM26700 is behaving better. I am going to replace the 4016's and 4050's (already did the 4011's) on the KAS board...

more later tonight.

--- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@...> wrote:
>
> Hmm ... continue refreshing the CMOS chips to newer parts and replace all capacitors maybe even the trimm pots for the SH, KAS boards. What about decoupling capacitors on the TKC board . Have you installed them when you replaced all the 4000 -CMOS chips there ?
>
> Should look like this after the repair/restore http://www.oldcrows.net/~oldcrow/synth/yamaha/cs80/CS80TKC3.jpg
>
>
>
>
> On Apr 18, 2010, at 1:40 PM, tmoravan wrote:
>
> > Good questions.
> >
> > Power supply has been recapped, new regulators, etc. I replaced the 4000 CMOS ICs on the TKC board. The synth was playing, but I was having weird problems like 1 voice would continue to sound (but I could still trigger new notes). I had been testing various cards trying to solve that problem and discovered a few wires had broken loose from their solder positions.
> >
> > The last round of testing - I had all the wires correctly soldered (they matched the color and positions in the service manual) and one of the lower boards (KAS, SH, TKC) shifted at some point and blew the 500mA fuses in the PS. I replaced the fuses, checked for obvious shorts (didn't find any), powered up without the large connector (I jumpered the +/- 15 and sense lines as stated in the docs) and checked all power supply voltages. They are all correct. I plugged the large connector back in, pulled the sense jumpers, and powered up. Voltages through the entire synth are correct and stable at all the boards. However, now I get no triggering of voices.
> >
> > --- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@> wrote:
> > >
> > > Hi ,
> > >
> > > Let us know what has been done/restored previously to this particular YAMAHA CS-80 ? Are the original 4000-Series CMOS chips still in there ? Have you started replacing some capacitors, yet ? How long have you had this machine ? Has it ever played (I mean while you have it ) ?
> > >
> > > Csaba
> > >
> > > On Apr 18, 2010, at 4:46 AM, tmoravan wrote:
> > >
> > > > OK - time to yell for help.
> > > >
> > > > Cleaning up a CS-80, and there's no voices sounding when playing a key. Started debugging at the KAS. All power looks good, note values are registering. Nothing appearing on the trigger outputs. Going backwards, the U1 -> U5 are mostly pegged at 8.48v and do not change no matter where on the keyboard I press.
> > > >
> > > > Is this a dead YM26600, or is there something else causing this?
> > > >
> > > > While I'm here, what should the clock input on pin 2 really look like? I'm not really seeing a stable square wave kind of oscillation there.
> > > >
> > > > thanks
> > > >
> > > >
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
>
>
>
> [Non-text portions of this message have been removed]
>

Great ! Keep up the good work . Remember the more you 'll replace the better it'll sound . Continue replacing 4000- CMOS chips . Now it would be a great to replace the chips on the SH board. See if get that stuck note checked of your list ;) .
Is it it always one note from the 8 you press ?

On Apr 21, 2010, at 12:11 AM, tmoravan wrote:

> Well, I have sound again. Now back to the 'stuck on' note and another with the wrong pitch. I replaced the two 4558's and the 2 4069's on the KAS and now the YM26600 and YM26700 is behaving better. I am going to replace the 4016's and 4050's (already did the 4011's) on the KAS board...
>
> more later tonight.
>
> --- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@...> wrote:
> >
> > Hmm ... continue refreshing the CMOS chips to newer parts and replace all capacitors maybe even the trimm pots for the SH, KAS boards. What about decoupling capacitors on the TKC board . Have you installed them when you replaced all the 4000 -CMOS chips there ?
> >
> > Should look like this after the repair/restore http://www.oldcrows.net/~oldcrow/synth/yamaha/cs80/CS80TKC3.jpg
> >
> >
> >
> >
> > On Apr 18, 2010, at 1:40 PM, tmoravan wrote:
> >
> > > Good questions.
> > >
> > > Power supply has been recapped, new regulators, etc. I replaced the 4000 CMOS ICs on the TKC board. The synth was playing, but I was having weird problems like 1 voice would continue to sound (but I could still trigger new notes). I had been testing various cards trying to solve that problem and discovered a few wires had broken loose from their solder positions.
> > >
> > > The last round of testing - I had all the wires correctly soldered (they matched the color and positions in the service manual) and one of the lower boards (KAS, SH, TKC) shifted at some point and blew the 500mA fuses in the PS. I replaced the fuses, checked for obvious shorts (didn't find any), powered up without the large connector (I jumpered the +/- 15 and sense lines as stated in the docs) and checked all power supply voltages. They are all correct. I plugged the large connector back in, pulled the sense jumpers, and powered up. Voltages through the entire synth are correct and stable at all the boards. However, now I get no triggering of voices.
> > >
> > > --- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@> wrote:
> > > >
> > > > Hi ,
> > > >
> > > > Let us know what has been done/restored previously to this particular YAMAHA CS-80 ? Are the original 4000-Series CMOS chips still in there ? Have you started replacing some capacitors, yet ? How long have you had this machine ? Has it ever played (I mean while you have it ) ?
> > > >
> > > > Csaba
> > > >
> > > > On Apr 18, 2010, at 4:46 AM, tmoravan wrote:
> > > >
> > > > > OK - time to yell for help.
> > > > >
> > > > > Cleaning up a CS-80, and there's no voices sounding when playing a key. Started debugging at the KAS. All power looks good, note values are registering. Nothing appearing on the trigger outputs. Going backwards, the U1 -> U5 are mostly pegged at 8.48v and do not change no matter where on the keyboard I press.
> > > > >
> > > > > Is this a dead YM26600, or is there something else causing this?
> > > > >
> > > > > While I'm here, what should the clock input on pin 2 really look like? I'm not really seeing a stable square wave kind of oscillation there.
> > > > >
> > > > > thanks
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > [Non-text portions of this message have been removed]
> > > >
> > >
> > >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>



[Non-text portions of this message have been removed]

OK - I know what the problem is for the stuck voice. The difficulty is fixing it. :-)

If I take voice card M4 out of the rack and move it around, the voice will either be stuck on or play normally. So, I believe one wire in that part of the harness has a break in it.

Anyone want to help guess which M card connection will create a "stuck on" voice if it is broken?

I can do this 2 ways - collect a probable list of wires and unsolder one at a time from a working card until I duplicate the problem or I can untie that part of the harness and pull/shake each wire...

Once this problem is solved I think the only thing left to do is a calibration.

--- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@...> wrote:
>
> Great ! Keep up the good work . Remember the more you 'll replace the better it'll sound . Continue replacing 4000- CMOS chips . Now it would be a great to replace the chips on the SH board. See if get that stuck note checked of your list ;) .
> Is it it always one note from the 8 you press ?
>
>
> On Apr 21, 2010, at 12:11 AM, tmoravan wrote:
>
> > Well, I have sound again. Now back to the 'stuck on' note and another with the wrong pitch. I replaced the two 4558's and the 2 4069's on the KAS and now the YM26600 and YM26700 is behaving better. I am going to replace the 4016's and 4050's (already did the 4011's) on the KAS board...

I wouldn't bother calibrating the thing until you replace ALL of the electrolytics and CMOS. I had several of each in mine that were failing.. ON EACH BOARD! Have you done anything to the SH board yet? I'd start looking for the stuck voice problems there. Paint brushes and plastic pens are good at finding broken connections.

-Mike

--- In yamahacs80@yahoogroups.com, "tmoravan" <moravanskyt@...> wrote:
>
> OK - I know what the problem is for the stuck voice. The difficulty is fixing it. :-)
>
> If I take voice card M4 out of the rack and move it around, the voice will either be stuck on or play normally. So, I believe one wire in that part of the harness has a break in it.
>
> Anyone want to help guess which M card connection will create a "stuck on" voice if it is broken?
>
> I can do this 2 ways - collect a probable list of wires and unsolder one at a time from a working card until I duplicate the problem or I can untie that part of the harness and pull/shake each wire...
>
> Once this problem is solved I think the only thing left to do is a calibration.
>
> --- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@> wrote:
> >
> > Great ! Keep up the good work . Remember the more you 'll replace the better it'll sound . Continue replacing 4000- CMOS chips . Now it would be a great to replace the chips on the SH board. See if get that stuck note checked of your list ;) .
> > Is it it always one note from the 8 you press ?
> >
> >
> > On Apr 21, 2010, at 12:11 AM, tmoravan wrote:
> >
> > > Well, I have sound again. Now back to the 'stuck on' note and another with the wrong pitch. I replaced the two 4558's and the 2 4069's on the KAS and now the YM26600 and YM26700 is behaving better. I am going to replace the 4016's and 4050's (already did the 4011's) on the KAS board...
>

Do other keys respond normally aside from the stuck note? I had problem where 8 notes stuck. Problem was bad CMOS hex inverter on the KAS board that generated the reset pulse for the YM2660 LSI.

Like Mike suggested, replace all your CMOS, 4558's and electrolytics. Good chance this will solve your problem. Regardless, these components need to be replaced.

Gavin Curtis
ModuleMaster/Circuit Solutions Inc.
2006 S Main
Moscow, ID 83843, USA
www.modulemaster.com
Tel: 208-892-0764/888-892-0764

--- On Thu, 5/27/10, mborish_2000 <mborish_2000@...> wrote:


From: mborish_2000 <mborish_2000@...>
Subject: [yamahacs80] Re: KAS / YM26600 question
To: yamahacs80@yahoogroups.com
Date: Thursday, May 27, 2010, 11:42 AM






I wouldn't bother calibrating the thing until you replace ALL of the electrolytics and CMOS. I had several of each in mine that were failing.. ON EACH BOARD! Have you done anything to the SH board yet? I'd start looking for the stuck voice problems there. Paint brushes and plastic pens are good at finding broken connections.

-Mike

--- In yamahacs80@yahoogroups.com, "tmoravan" <moravanskyt@...> wrote:
>
> OK - I know what the problem is for the stuck voice. The difficulty is fixing it. :-)
>
> If I take voice card M4 out of the rack and move it around, the voice will either be stuck on or play normally. So, I believe one wire in that part of the harness has a break in it.
>
> Anyone want to help guess which M card connection will create a "stuck on" voice if it is broken?
>
> I can do this 2 ways - collect a probable list of wires and unsolder one at a time from a working card until I duplicate the problem or I can untie that part of the harness and pull/shake each wire...
>
> Once this problem is solved I think the only thing left to do is a calibration.
>
> --- In yamahacs80@yahoogroups.com, Csaba Zvekan <czvekan@> wrote:
> >
> > Great ! Keep up the good work . Remember the more you 'll replace the better it'll sound . Continue replacing 4000- CMOS chips . Now it would be a great to replace the chips on the SH board. See if get that stuck note checked of your list ;) .
> > Is it it always one note from the 8 you press ?
> >
> >
> > On Apr 21, 2010, at 12:11 AM, tmoravan wrote:
> >
> > > Well, I have sound again. Now back to the 'stuck on' note and another with the wrong pitch. I replaced the two 4558's and the 2 4069's on the KAS and now the YM26600 and YM26700 is behaving better. I am going to replace the 4016's and 4050's (already did the 4011's) on the KAS board...
>








[Non-text portions of this message have been removed]