TLDR: Analog board adjustment has been made to no avail, compressed picture persists across multiple known good analog boards that show full picture with other logic boards. Confirming problem is on the logic board).
I recently picked up an SE/30 for a steal but it had a Simasimac screen with some distortion (also, although I didn't dig into it at the time, the simasimac screen was compressed vertically, meaning it did not take up the entire height of the screen). Here's the starting point:
I cleaned the board well (it was filthy and I suspect an animal or insects had been living in it, given the significant amount of debris / black stuff on the board). I replaced all the caps on the logic board, and the problem persisted.There appears to have been other work done on this SE/30 previously, so I decided to replace everything I could. I removed the RAM, ROM, Video ROM, all the chips at UC6/7. UE6/7, UG6/7, UI6 and replaced them with known good chips from another board. Problem remained. I traced the problem to the video RAM chips (which on this machine were generic chips with zero markings on them). Once I replaced those with new chips, the board would give me a boot chime and a gray screen (compressed vertically).
After troubleshooting some RAM problems, I was able to successfully boot into System 6, but the video was still compressed. No big deal, I thought. "I'll just adjust the screen height on the analog board". Sadly, the height adjustment was already almost at its highest. The video signal must not be sending the full width.
The traces on the board actually all look very good. I specifically checked around UE8 because I had another SE/30 that had issues with UE8 and it was due to corrosion of the legs of UE8 and replacing the chip solved that problem. I can replace it, but this problem feels different. Anyone seen this before or know what might control the horizontal video output for the SE/30. I looked through the Dead Mac Scrolls and didn't see anything that matches this problem.
PS. Here's a look at the board - it cleaned up pretty well.
I recently picked up an SE/30 for a steal but it had a Simasimac screen with some distortion (also, although I didn't dig into it at the time, the simasimac screen was compressed vertically, meaning it did not take up the entire height of the screen). Here's the starting point:
I cleaned the board well (it was filthy and I suspect an animal or insects had been living in it, given the significant amount of debris / black stuff on the board). I replaced all the caps on the logic board, and the problem persisted.There appears to have been other work done on this SE/30 previously, so I decided to replace everything I could. I removed the RAM, ROM, Video ROM, all the chips at UC6/7. UE6/7, UG6/7, UI6 and replaced them with known good chips from another board. Problem remained. I traced the problem to the video RAM chips (which on this machine were generic chips with zero markings on them). Once I replaced those with new chips, the board would give me a boot chime and a gray screen (compressed vertically).
After troubleshooting some RAM problems, I was able to successfully boot into System 6, but the video was still compressed. No big deal, I thought. "I'll just adjust the screen height on the analog board". Sadly, the height adjustment was already almost at its highest. The video signal must not be sending the full width.
The traces on the board actually all look very good. I specifically checked around UE8 because I had another SE/30 that had issues with UE8 and it was due to corrosion of the legs of UE8 and replacing the chip solved that problem. I can replace it, but this problem feels different. Anyone seen this before or know what might control the horizontal video output for the SE/30. I looked through the Dead Mac Scrolls and didn't see anything that matches this problem.
PS. Here's a look at the board - it cleaned up pretty well.
