problem w/ a prophet 600

[Tom Priore]

Hey I got an old prophet 600 that is giving me a hard time..
Its a digitally controlled analog synth, and some times the digital control
stops working. I can still play it, I just cant change the sounds. Sometimes
it will start working again if I play with the knobs or turn it off and on,
but other times, i just gotta give up for the day.
This problem used to happen every once I a while but now its like every day.
I have a theory it could be heat related, but i'm not sure. I realy wouldnt
even know how to test for that. My worst fear is that its the rom going.
I'm and EE student and i got and Oscope and a bunch of other toys avalibe,
but i dont know where to start looking.
Thanks
Tom