Patches and discussion for Ensoniq VFX family

I bought a SD1-32 and unfortunately it was in an awful condition, lots of
dust, sticky liquids in the keyboard etc..
After some cleaning and repair I got it to work but...
The sound is still distorted, unstable, sometimes fading or wandering from
side to side. It sounds like if you have got a bad cable or a bad connector
but it's the same from all outputs.
When I control a second keyboard from the SD1 everything works fine
including the pitch and mod wheels. The other way round, that is when I
control the SD1 from the other keyboard I have the same problem. 

Any idea?

Hans