I replaced the performance chip on my 1994 325i E36. All seemed to go well, until putting the DME back into place. That's when I touched to DME housing to the positive battery lead and threw a spark! I know, always disconnect the battery. I will never ever forget again. But now what? A salvaged DME is $250. Is that my best option, or may there be a more simple fix (resetting computer, checking fuses, surge protector inside the DME)?