portableleo
New member
Hi Everyone,
I have a Macintosh Color Classic that stopped working a few months ago - based on my readings of previous posts I'm 99% sure that there is an issue with the analog board:
Symptoms:
- Computer was working but after a few hours the fan failed, and I didn't notice. Eventually the computer began to overheat and then it died.
- Original logic board was recapped from the beginning.
- Original analog board was recapped, but it was totally dead and not revivable. Green LED flashes but no boot.
- Got a replacement recapped analog board from eBay - seller insists board was fully functional (has photos to prove it etc)
- When new board was installed, it worked for about 20-30 seconds (see video here:
), but video signal was messy and was dropping out. Strange buzzing sounds could be heard. Since this video, computer will reboot, but the screen is totally blank.
- When booting cold (unplugged for an hour), screen will degauss during boot ("thump" then faint buzz during power on)
- When running, can hear faint buzz near flyback / neck of CRT
- Computer will boot via ADB keyboard (chime and floppy disk reads)
Considering to replace some diodes and the Optocouplers, but would be great if someone who is more familiar with the electronics of the analog board could point me in the right direction, thank you!!
I have a Macintosh Color Classic that stopped working a few months ago - based on my readings of previous posts I'm 99% sure that there is an issue with the analog board:
Symptoms:
- Computer was working but after a few hours the fan failed, and I didn't notice. Eventually the computer began to overheat and then it died.
- Original logic board was recapped from the beginning.
- Original analog board was recapped, but it was totally dead and not revivable. Green LED flashes but no boot.
- Got a replacement recapped analog board from eBay - seller insists board was fully functional (has photos to prove it etc)
- When new board was installed, it worked for about 20-30 seconds (see video here:
- When booting cold (unplugged for an hour), screen will degauss during boot ("thump" then faint buzz during power on)
- When running, can hear faint buzz near flyback / neck of CRT
- Computer will boot via ADB keyboard (chime and floppy disk reads)
Considering to replace some diodes and the Optocouplers, but would be great if someone who is more familiar with the electronics of the analog board could point me in the right direction, thank you!!
