Vintage Synth Repair

Hi, all.

I recently received a Crumar DS-1 over eBay.  It appears to have been damaged in 
shipping.

Groups of keys are playing in the wrong octave.  They vary randomly, but digitally.  They 
vary so rapidly that if I play a sweep upwards and then downwards, the keys will have 
changed to other octaves on the way down.

I have no schematics, so I have no idea where the problem may be, although I do know 
that the row of boards on the left probably suffered impact as the plastic bar that holds 
them in place was snapped and sitting on top of them.  When I reposition the front-most 
board by reseating it, the keys will change octaves.  Sometimes this will cause them to stay 
constant (still wrong) for extended periods.

Should I just reheat each solder joint on this board?

If someone has schematics or knows what might be wrong, please let me know!