I've just bought an Oberheim Stretch DX which was generally in a nice condition, but had a few switches on the Stretch side which weren't functioning properly. A bit of contact cleaner fixed one of them but two remained faulty. As the switch caps were fixed quite tightly, removing them had pulled the switches up from the board, so reasoning that the contacts between the board and the switches may have been compromised, I gave the joints a quick dab of the soldering iron - bad idea, I suspect.
Now, when the unit is turned on, all voices trigger in unison, and the display flashes up a load of vertical lines, then everything goes dead. I've tried disconnecting the stretch from the DX with no improvement. Does this sound like Ive fried something important on the main board? Does anyone know how I might go about testing for the faulty element? I'd like to see if I can sort it out before I send it for repair, as I'm skint.