Hey everyone! This is my first post here, nice to meet you all. I am on the new side to synth repair, the background i have is mostly in combo organs, but i’m trying to cover all bases of keyboard repair. I have a roland sh1000 that is barely making any noise. The only thing im hearing is a very very quiet and high indefinite note of whatever key i press. The tabs and knobs do nothing to affect the the sound. I recapped the power supply board but that has done nothing. Can anyone point me in the right direction to start troubleshooting this thing? Any and all help is appreciated!
Get the service manual from http://www.synfo.nl/ (they are for free, but don’t forget to support the site owner, who scanned them carefully, via paypal)
Get a oscilloscope and trace the signals VCO -> VCF -> VCA.
Check also the CV and Gate Signal
A generic problem of those old synths are corroded switches and potentiometers.
To my experience one should not start with any fault tracing unless you haven’t cleaned or replaced each and every potentiometer and switch.