I made the stupid mistake of plugging an adjustable AC adapter into my 4 track digital recorder, its a Korg PXR4 or a toneworks, anyways, it takes 4.5v 500 milliamps, and I introduced it to 6 volts and I don't remember how many amps.  Is there a typical component that fails when this occurs, or am I just totally up a creek?  The unit tries to come on, the LCD is dimly lit and once in a while a function seems to work. :-