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siel dk-600

siel dk-600

2008-03-01 by cockandswan

hey, i just got a siel dk-600 which i am excited about. it's different
than the older synths i've been working on but i thought i'd see if
anyone else has any experience trouble shooting these. 

problems:

it powers up but there's no sound and no response form the
buttons/nobs. one of the LEDs is burned out too. i'm hoping that since
all the nobs and buttons are non-functional that there is some master
routing for the controls that has gone bad. any ideas? how about led
replacements? 

thanks for all your help guys!
-johnny

RE: [vintagesynthrepair] siel dk-600

2008-03-01 by Scott Nordlund

I have a broken DK 600 (with Expander) myself that I hopefully will be working on shortly. Get the Opera 6 service manual from Sander Meyer's website- it *should* be the same as the DK 600 (though I have heard all sorts of confusing and contradictory info about the Opera 6 and DK 600- you may want to verify, just to be sure, that it corresponds to what you're actually working on).

The main problem with the DK 600 (other than the fact that it's a Siel) is the NiCd memory backup battery, which leaks onto the CPU board (like in the Polysix). So the first thing you'll want to do is check out the CPU board (under the keyboard) and see what's going on under there. In anticipation of fixing mine, I've analyzed the problems that a leaky battery can cause, depending on what chips are affected. If IC15 or IC16 are bad, the front panel buttons and/or tape dump won't work (IC15 buffers panel inputs, IC16 buffers the tape dump in/out and the front panel "data available" interrupt signal). IC20 controls waveform selection. IC28 and IC29 control display blanking and the "Enter" LED. I don't know what would cause the knobs to not work- check TP8 (multiplexed knob readings). There also should be LEDs on the voice board connected to gate signals, so you can see if the voices are being properly triggered.
Show quoted textHide quoted text
To: vintagesynthrepair@yahoogroups.com
From: cockandswan@...
Date: Sat, 1 Mar 2008 03:26:56 +0000
Subject: [vintagesynthrepair] siel dk-600

hey, i just got a siel dk-600 which i am excited about. it's different
than the older synths i've been working on but i thought i'd see if
anyone else has any experience trouble shooting these.

problems:

it powers up but there's no sound and no response form the
buttons/nobs. one of the LEDs is burned out too. i'm hoping that since
all the nobs and buttons are non-functional that there is some master
routing for the controls that has gone bad. any ideas? how about led
replacements?

thanks for all your help guys!
-johnny



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Re: siel dk-600

2008-03-01 by cockandswan

Thanks, I'll take a closer look at those ICs shortly. I did some tests
and none of the LEDs on the voice board are triggered by the keyboard.
Also I noticed that when I flick it on and off a few times sometimes
the LF) 1/2 rate LED is off and other times it's solid on. The rate
nob doesn't control it at all. I looked at the battery and it doesn't
LOOK like it's leaked onto anything, but I'm still gonna test those
chips (or just replace them.)

I'm beginning to wonder if the problem isn't related to the power not
getting to some of the boards... hmmm....



--- In vintagesynthrepair@yahoogroups.com, Scott Nordlund <gsn10@...>
wrote:
>
> 
> I have a broken DK 600 (with Expander) myself that I hopefully will
be working on shortly.  Get the Opera 6 service manual from Sander
Meyer's website- it *should* be the same as the DK 600 (though I have
heard all sorts of confusing and contradictory info about the Opera 6
and DK 600- you may want to verify, just to be sure, that it
corresponds to what you're actually working on).
> 
> The main problem with the DK 600 (other than the fact that it's a
Siel) is the NiCd memory backup battery, which leaks onto the CPU
board (like in the Polysix).  So the first thing you'll want to do is
check out the CPU board (under the keyboard) and see what's going on
under there.  In anticipation of fixing mine, I've analyzed the
problems that a leaky battery can cause, depending on what chips are
affected.  If IC15 or IC16 are bad, the front panel buttons and/or
tape dump won't work (IC15 buffers panel inputs, IC16 buffers the tape
dump in/out and the front panel "data available" interrupt signal). 
IC20 controls waveform selection.  IC28 and IC29 control display
blanking and the "Enter" LED.  I don't know what would cause the knobs
to not work- check TP8 (multiplexed knob readings). There also should
be LEDs on the voice board connected to gate signals, so you can see
if the voices are being properly triggered.
> 
> To: vintagesynthrepair@yahoogroups.com
> From: cockandswan@...
> Date: Sat, 1 Mar 2008 03:26:56 +0000
> Subject: [vintagesynthrepair] siel dk-600
> 
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>             hey, i just got a siel dk-600 which i am excited about.
it's different
> 
> than the older synths i've been working on but i thought i'd see if
> 
> anyone else has any experience trouble shooting these. 
> 
> 
> 
> problems:
> 
> 
> 
> it powers up but there's no sound and no response form the
> 
> buttons/nobs. one of the LEDs is burned out too. i'm hoping that since
> 
> all the nobs and buttons are non-functional that there is some master
> 
> routing for the controls that has gone bad. any ideas? how about led
> 
> replacements? 
> 
> 
> 
> thanks for all your help guys!
> 
> -johnny 
> 
> 
> 
> 
>       
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>     
>     
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> 
> _________________________________________________________________
> Need to know the score, the latest news, or you need your
HotmailĀ®-get your "fix".
> http://www.msnmobilefix.com/Default.aspx
>

RE: [vintagesynthrepair] Re: siel dk-600

2008-03-02 by Scott Nordlund

I would guess that the CPU isn't doing anything at all. Probably the LFO rate on/off thing is due to some latch somewhere that just comes up in some arbitrary state and never gets changed by the CPU. Probably the chips around the battery aren't the problem (or at least not the biggest problem).

Test the power supply, check the power to the chips on the CPU board, check for bad connections and faulty ribbon cables, reseat connectors (be very careful, the pins are easy to break) and socketed chips. Look for signs of any activity- the keyboard is scanned directly by the CPU, so look for activity on those lines, or on the other CPU bus lines. Make sure the CPU is getting a clock signal.

Something should be working at least, even if the CPU isn't working- check TP34 (I think that's it- the schematic is hard to read) for a high frequency signal- the master oscillators should be running.
Show quoted textHide quoted text
To: vintagesynthrepair@yahoogroups.com
From: cockandswan@...
Date: Sat, 1 Mar 2008 19:39:20 +0000
Subject: [vintagesynthrepair] Re: siel dk-600

Thanks, I'll take a closer look at those ICs shortly. I did some tests
and none of the LEDs on the voice board are triggered by the keyboard.
Also I noticed that when I flick it on and off a few times sometimes
the LF) 1/2 rate LED is off and other times it's solid on. The rate
nob doesn't control it at all. I looked at the battery and it doesn't
LOOK like it's leaked onto anything, but I'm still gonna test those
chips (or just replace them.)

I'm beginning to wonder if the problem isn't related to the power not
getting to some of the boards... hmmm....

--- In vintagesynthrepair@yahoogroups.com, Scott Nordlund
wrote:
>
>
> I have a broken DK 600 (with Expander) myself that I hopefully will
be working on shortly. Get the Opera 6 service manual from Sander
Meyer's website- it *should* be the same as the DK 600 (though I have
heard all sorts of confusing and contradictory info about the Opera 6
and DK 600- you may want to verify, just to be sure, that it
corresponds to what you're actually working on).
>
> The main problem with the DK 600 (other than the fact that it's a
Siel) is the NiCd memory backup battery, which leaks onto the CPU
board (like in the Polysix). So the first thing you'll want to do is
check out the CPU board (under the keyboard) and see what's going on
under there. In anticipation of fixing mine, I've analyzed the
problems that a leaky battery can cause, depending on what chips are
affected. If IC15 or IC16 are bad, the front panel buttons and/or
tape dump won't work (IC15 buffers panel inputs, IC16 buffers the tape
dump in/out and the front panel "data available" interrupt signal).
IC20 controls waveform selection. IC28 and IC29 control display
blanking and the "Enter" LED. I don't know what would cause the knobs
to not work- check TP8 (multiplexed knob readings). There also should
be LEDs on the voice board connected to gate signals, so you can see
if the voices are being properly triggered.
>
> To: vintagesynthrepair@yahoogroups.com
> From: cockandswan@...
> Date: Sat, 1 Mar 2008 03:26:56 +0000
> Subject: [vintagesynthrepair] siel dk-600
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>;
>
> hey, i just got a siel dk-600 which i am excited about.
it's different
>
> than the older synths i've been working on but i thought i'd see if
>
> anyone else has any experience trouble shooting these.
>
>
>
> problems:
>
>
>
> it powers up but there's no sound and no response form the
>
> buttons/nobs. one of the LEDs is burned out too. i'm hoping that since
>
> all the nobs and buttons are non-functional that there is some master
>
> routing for the controls that has gone bad. any ideas? how about led
>
> replacements?
>
>
>;
> thanks for all your help guys!
>
> -johnny
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
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>
>
> __________________________________________________________
> Need to know the score, the latest news, or you need your
HotmailĀ®-get your "fix".
> http://www.msnmobilefix.com/Default.aspx
>



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