I successfully added the PWM mod and the other FM mods on this site -
Unfortunately, adding the In3 and in4 mods has made my keyboard non-functional except the first 7 or 8 keys.
Everything has now been de-soldered and the photos of the places i soldered is here:
When I turn on the machine I get two clicking sounds. The MS20 works fine via MIDI but behaves like it has a note held once I press a note on the keyboard.
Here is the synth being turned on:
I've learnt a lot from this, and would be very grateful for any help with getting this synth back to normal.