PacificState
Well-known member
After resolving the power supply issue with a bad switch (https://68kmla.org/bb/index.php?thr...ltages-at-floppy-connector.39895/#post-430859), I then booted the Mac to be greeted by a working fan and... a continual but quiet ticking sound with no chime and a black screen (this isn't where I ended up, so read on!).
So far, I've:
- Swapped in a known good logic board, to no effect
- Recapped the power supply and tested the voltages - they seem a little bit off unloaded, but I think that's expected. This didn't affect the tick.
- Followed the guide for a black screen at https://wiki.preterhuman.net/Macintosh_SE/30 and swapped out CR2, CR3, CR5, and Q2 - I still got the tick.
- Thinking the tick was maybe indicative of a bad flyback, I swapped in a working analog board. At this stage, I now hear the chime at boot and no tick, but there's still no display.
At this point, I can only think it's either the video board or the CRT itself. Is there any way to diagnose?
So far, I've:
- Swapped in a known good logic board, to no effect
- Recapped the power supply and tested the voltages - they seem a little bit off unloaded, but I think that's expected. This didn't affect the tick.
- Followed the guide for a black screen at https://wiki.preterhuman.net/Macintosh_SE/30 and swapped out CR2, CR3, CR5, and Q2 - I still got the tick.
- Thinking the tick was maybe indicative of a bad flyback, I swapped in a working analog board. At this stage, I now hear the chime at boot and no tick, but there's still no display.
At this point, I can only think it's either the video board or the CRT itself. Is there any way to diagnose?