68kMLA Classic Interface
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| Click here to select a new forum. | | Macintosh IIsi possible video glitch | Posted by: MrArthegor on 2026-03-20 13:22:29
Hello everyone,
I’ve recovered a Macintosh IISi in good condition except for the PSU which had a significant capacitor leakage. The electrolyte was practically in the motherboard PSU connector.
Naturally, I removed all the caps, thoroughly cleaned the remaining electrolyte and re-capped the PSU. I’ve also re-capped the Logic Board.
Now the computer starts but the video output signal is strange with a wobble in the background. I’m using an OSSC with a standard DA-15 to VGA adapter but I’m struggling to determine if this issue stems from the OSSC or the Macintosh. (Of course, I only have the OSSC to test and my other old monitor doesn’t support RGB.)
Here’s a link to the video of the effect. If anyone has an idea I’d be very grateful.
Thanks for reading and sorry if I make any English mistakes; it’s not my native language.
| Posted by: Byrd on 2026-03-20 14:27:40
The wobble/shimmering looks like a result of the OSSC or your LCD sync - can you try another monitor LCD or ideally CRT. | Posted by: MrArthegor on 2026-03-20 23:48:29
Thank you for your comment, indeed, It’s an OSSC issue I was able to find a monitor with sync on green (pretty hard to find in LCD, one 4 monitor I have check only 1 was ok)
I’m going to try to fix the OSSC settings, but before that I need to make the IIsi more reliable because it’s seem to have sporadic issue with shutdown, and sad Mac boot | Posted by: bibilit on 2026-03-20 23:49:26
Yes, nothing wrong with it, your LCD is not playing nice with the IIsi.
As Byrd says CRT is the best option. | | 1 |
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