E-Mu XBoard61 Midi Keyboard Controller PCB (Burnt?)

I left a 12V adapter plugged into my XBoard61 for too long and began to smell electrical burning. The keyboard only allows 6V, and I now wonder:

1. Did only the PCB burn up ? How can the PCB be tested to see if it is the sole damaged component?
2. Where could I purchase a replacement PCB?

The PCB model appears to be "EM7700" and is apparently the same PCB that is in all three XBoard versions (61, 49, and 25 keys). If the price is right for a replacement PCB, I'd really love to keep this keyboard.

Anybody know of a good online source for replacement PCBs or from a location within the U.S.A.?

EDIT: When I use battery power (AAA Batteries), the LED display works until I plug the USB into my computer. It will light-up when connected to the MIDI keyboard, but will fade out one connected to the computer. Anyone have insight?