Roland SH 2000 problems

[operasix]

Hey boys and girls,

I'm dealing with some problems on my roland sh2000

It started like this:

the sh2000 started to make dropouts while playing. these were getting more. I noticed that when I opened the lid and did a smooth push to the pcb anywhere it worked again for a while.

now last week it it started again with dropouts but this time more with volume changing in the sound.
so sometimes the sound was okay and while pressing the same key again and again it changed its volume or there was no sound randomly.

what I did so far:

- I checked the psu and I am getting +15 and -15 Volts
- I renewed IC555
- cleaned and checked all contacts on the pcbs
- did lots of soldering on the vcf / vca board (because it reacted to little movements)
- I checked VCF board pin 8 and I have signal when playing keys
- I checked VCF board pin 10 (mute signal) and this looks a bit strange. when I press a key it rises but when I release the key it doesnt fall down but releases very very slow ...
- I cleaned and trimmed the potis (noise, reso, dc offset, cut off, vcf width)
I noticed that when I turn up the vca width poti that I have sound on all keys (presets and white noise) again but now I have an endless sustain.
- Filter in manual mode also works but cutoff seems to have a very small range.

No I don't have any ideas anymore.

Why don't I get a sound if vca width poti is in it old factory marked position ?

I have the service manual but I ran out of ideas what to do now ? Anyone had the same issue or any other ideas ?

thanks for your help guys.

all the best
steff

[madtheory]

Check the multipin connectors on each board.

[upunkt]

I've had an issue with my SH-2000 quite a while that I could not track properly first. The issue was, the first note you played after switching on got repeated/triggered constantly at a certain rate that could not be influenced by the LFO or the random note switch.
Eventually I noticed that ground was missing on VCO Board 2. It turned out to be a broken trace at the rear edge of the MX main board. This could not be seen, only continuity checks disclosed this. It's tough to check all the traces, but I recommend doing it at some point when you're stuck. Good luck!

[squidmask]

I picked one up recently and am getting power but absolutely no sound. I have some very basic knowledge so i cleaned all the contacts, deoxit on pretty much anything that needed it which wasn’t much. I’m far from an expert but i can’t seem to figure out why wouldn’t even get a signal. Is it as simple as a bad output? I moved knobs, flipped switches, nothing. Not even a hum or a crackle. My interface is hooked up properly and was tested beforehand. I really don’t want to mess with too much but I’m just wondering what an absolutely dead signal with power could be. Fuses? They looked fine to me

[madtheory]

I’m far from an expert...

Sorry, but there's your answer. This synth needs an expert.