Hey all-
Long-time listener, first-time caller.
I'm finally getting down to brass tacks with my full 720º restore, and the only real hurdle I'm running into is a pretty major one: scrambled output from the board(s). When I first picked up the machine, last year, it was booting to the 6502 Audio Processor error:
At some point after removing the boards, reseating chips, checking traces and some transistors (all seemed fine), it got WORSE and started booting to THIS instead:
I'm worried that something got zapped when I was re-connecting the boards. I've gone ahead and replaced both crystals on the CPU board (I've read that they are common failure points) and all of the electrolytic capacitors on both boards. Still, no change.
I hear no boot sounds, nothing. And no, the test switch on the audio board does nothing to help.
Any suggestions? I've got the logic probe ready to start checking signals and I'm not against ordering replacement chips for the 6502 and T11.
Thanks in advance,
Kasey
Long-time listener, first-time caller.
I'm finally getting down to brass tacks with my full 720º restore, and the only real hurdle I'm running into is a pretty major one: scrambled output from the board(s). When I first picked up the machine, last year, it was booting to the 6502 Audio Processor error:
At some point after removing the boards, reseating chips, checking traces and some transistors (all seemed fine), it got WORSE and started booting to THIS instead:
I'm worried that something got zapped when I was re-connecting the boards. I've gone ahead and replaced both crystals on the CPU board (I've read that they are common failure points) and all of the electrolytic capacitors on both boards. Still, no change.
I hear no boot sounds, nothing. And no, the test switch on the audio board does nothing to help.
Any suggestions? I've got the logic probe ready to start checking signals and I'm not against ordering replacement chips for the 6502 and T11.
Thanks in advance,
Kasey

