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| Mystery IIsi that chimes, but has no video, and won't boot! |
Posted by: franklyn on 2024-03-11 04:20:28
I also had the problem that the start sound was fine but the computer didn't bring up a picture onto the monitor and didn't boot. The reason was bad contacts (oxidized) on the video controller chip. New/re-soldered and now everything is good ...
On other computer systems there are diagnostic modules and a null modem serial connection to another computer with a terminal program. Is there something like this for the Macintosh 68k series? |
Posted by: Garrett B on 2024-03-11 08:06:49
I see some corrosion near the power connector as well. Checked this as well - good continuity just missing some solder mask is all. |
Posted by: Garrett B on 2024-03-11 08:10:28
I also had the problem that the start sound was fine but the computer didn't bring up a picture onto the monitor and didn't boot. The reason was bad contacts (oxidized) on the video controller chip. New/re-soldered and now everything is good ...
On other computer systems there are diagnostic modules and a null modem serial connection to another computer with a terminal program. Is there something like this for the Macintosh 68k series? When you say "video controller chip" you're talking about the RBV chip at UA3? |
Posted by: franklyn on 2024-03-11 08:59:15
Video are UA2 (RamDAC) and UA3 (Video Chip) I think ... |
Posted by: Garrett B on 2024-03-11 09:07:22
On other computer systems there are diagnostic modules and a null modem serial connection to another computer with a terminal program. Is there something like this for the Macintosh 68k series? You bring up a good point here. I've done some serial diagnostic work on a Portable but didn't even think to try the IIsi. I know it's supported - just need to figure out syntax for the right tests to run. Unfortunately a lot of this isn't super well documented. I'll post back though when I have a chance to get serial set up. That is, if serial is working. Fingers crossed! |
Posted by: corbinq27 on 2024-10-25 23:00:56
I've got a IIsi that just started doing this after I recapped it. ugh. Honestly I did also do an isopropyl bath as well. I wonder if I got some corrosion slurry to form under a chip in the process.
Curious how this is going for you? |
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