OBERHEIM SYNTH

I just got my OB-8 out of storage after 6 years and everything lights up and all the functions seem to work (lights switch), but no sound at all.  I replaced the battery on the board and even tried loading factory patches from a WAV file.  I was able to hear the WAV file through the Mono Out, although the keyboard would not run through the patch loading sequence.  Every other time I tried loading the patches, I did NOT hear the sound passing through the Mono Out (or L or R outs).  This seems related to the no sound problem I started off with.

I've heard that the first things to go are the capacitors, particularly the ones on the power supply board.  Should I just replace those?  I also noticed that the cassette switch on the back of the machine is sloppy.  I should probably replace that as well, huh?

Any other ideas as to what might be causing the no sound problem?

Thanks!

jeff