Mitchell Spector wrote:
Another update: I decided to have a closer inspection at the solder joints on the backside of my ZipGS, so I used my flatbed scanner as a sort of digital magnify glass. I spotted what appears to be a bad solder joint on one of the loweroscillator socket pins (by no coincidence, this is also the area where when touched, will cause the cache LED to flicker on and off). It looks like all the solder around the pin dried out and is missing.Here's a shot, showing the backside of the oscillator socket: http://www.digitalsparkles.com/student_a/ZipGS1.jpg Here's an close up of that suspect pin: http://www.digitalsparkles.com/student_a/ZipGS2.jpg My only concern is why pressing on it (to temporarily rebridge the connection) still leaves the GS in a dead state. I'll try it in another motherboard tomorrow but I think getting someone to resolder thispin will be the first step.
This is clear evidence of a bad soldering job done with too hot an iron. I'd also worry about any other resoldered joints on the card (done by the modifier). It is likely that careful resoldering of these joints will fix at least the oscillator problem. Think about how this happened: It worked until you pressed down hard on the top of the card and the IDC connector in the CPU socket. *That* was the act that changed an intermittent fault into a solid fault--and for that you should be happy, since a solid fault can be found and fixed, while an intermittent fault can be elusive. Don't look for complicated or improbable faults when simple mechanical stress is almost certainly the source of the problem. -michael New, faster SUDOKU v2.0 solver for Apple II's! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."