Vintage Synth Repair

jamie,
mike's advice is good- this is the same problem that caused the
infamous "insane" behaviour in early/unmodified moog source units; in
that case, the series regs were not soldered at all, but sat loosely
in a connector. removing this & soldering them in place would cure the
moog but meant exercising extra care when removing the case for other
surgery.
it's possible you may have CPU problems though- I have had a 106 in
bits that lost it's mind after "liquid ingress"; the board around the
CPU is quite sensitive & it may just need a clean to remove something
that's deposited there & is "C-shunting" across some CPU connections;
anything that can be carried in the air can settle on a pcb & cause
this, especially if there's dry-ice or smoke involved... :-)

duncan.