Doh! Thanks, yes, embarrassingly that was the problem!
Managed to fix the keyboard by replacing IC34. The chip was shorting.
Got DCO 2 back to life, tracked it down to IC18 missing a connection.
Now I have a problem with the pitch bend. I get correct readings at IC10 pin 7 as described in the service manual. But the pitch bend seems to do the reverse of what you would expect.
Reading pin 7 of IC35 with the pitch bend in centre I get 0.7v, with it up it goes to -3V, down it goes to +3.5V. Is this behaviour correct? As I side not the synth sounds alot better tuning wise when the pitch bender is disconnected. I have read the resistance of the pitch pot and it seems to be functioning as you would expect.
Thanks again,
Al
Managed to fix the keyboard by replacing IC34. The chip was shorting.
Got DCO 2 back to life, tracked it down to IC18 missing a connection.
Now I have a problem with the pitch bend. I get correct readings at IC10 pin 7 as described in the service manual. But the pitch bend seems to do the reverse of what you would expect.
Reading pin 7 of IC35 with the pitch bend in centre I get 0.7v, with it up it goes to -3V, down it goes to +3.5V. Is this behaviour correct? As I side not the synth sounds alot better tuning wise when the pitch bender is disconnected. I have read the resistance of the pitch pot and it seems to be functioning as you would expect.
Thanks again,
Al