Hello.
I need help to hopefully fix this. I used to have two Mac Pluses, sold one a while back but recently the new owner asked for help, since it stopped booting. Not sure what use the machine had (if any) but here's what the Mac does when turned on:
https://vimeo.com/1208991261?fl=pl&fe=sh
Since I had the other machine working correctly, and my knowledge of electronics is barely basic (I can solder and desolder components, but I only have a basic multimeter and not really a lot of experience to correctly use it) I decided to swap parts around since nothing was evidently broken. The analog board was confirmed good with the other logic board, and then I swapped RAM sticks and the ROM chips from one logic board to the other, but one always failed the same. I tried resoldering the connector from the analog board, the ROM sockets and the RAM holders, since the failing logic board has duller-looking soldering points than the one that works, but it still fails to boot and starts chaging patterns as visible in the video, until it stops.
I will attach pictures of the logic board, is worth noting that the scratches on the bottom were covered by the previous owner (the person I bought the machine from and not the one that bought it from me) with the green UV solution (or nail polish, not sure), and I confirmed there is correct continuity despite them.
I sent the other Mac with the working logic board and kept the bad one with the idea to fix it, so I can no longer test by swapping components.
Thanks in advance for the help!
I need help to hopefully fix this. I used to have two Mac Pluses, sold one a while back but recently the new owner asked for help, since it stopped booting. Not sure what use the machine had (if any) but here's what the Mac does when turned on:
https://vimeo.com/1208991261?fl=pl&fe=sh
Since I had the other machine working correctly, and my knowledge of electronics is barely basic (I can solder and desolder components, but I only have a basic multimeter and not really a lot of experience to correctly use it) I decided to swap parts around since nothing was evidently broken. The analog board was confirmed good with the other logic board, and then I swapped RAM sticks and the ROM chips from one logic board to the other, but one always failed the same. I tried resoldering the connector from the analog board, the ROM sockets and the RAM holders, since the failing logic board has duller-looking soldering points than the one that works, but it still fails to boot and starts chaging patterns as visible in the video, until it stops.
I will attach pictures of the logic board, is worth noting that the scratches on the bottom were covered by the previous owner (the person I bought the machine from and not the one that bought it from me) with the green UV solution (or nail polish, not sure), and I confirmed there is correct continuity despite them.
I sent the other Mac with the working logic board and kept the bad one with the idea to fix it, so I can no longer test by swapping components.
Thanks in advance for the help!
