68kMLA Classic Interface

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croissantking's conquests

Posted by: pizzigri on 2025-09-25 15:53:12 No, but I can try to remove both original audio ports from a fried board I have…. Possibly even the SCSI port. dunno about the choke though.

Posted by: pizzigri on 2025-09-26 00:34:49 Drop me a line…

Posted by: MBehr on 2025-09-26 10:48:04 This looks so much better than what I would have expected! Good luck with the Egret…

Posted by: croissantking on 2025-11-01 04:13:44 Progress with my spare 840AV board. I discovered why it wasn’t outputting video. It turns out the DAC (or what I think must be the DAC) wasn’t receiving a required -5V input. I traced this back to the voltage regulator that was instead outputting 0.65V. Yeah, that’s not going to work. So I checked its input and found 0V, but it should be -12V. Aha! There’s a break in continuity of an internal trace running back to the -12V pin of the PSU. One bodge wire later, and I’m now getting video output: Another issue I was having is resolved too, namely that some Nubus cards weren’t working. This was due to the missing -12V feed. There’s one outstanding issue with this board - sound output doesn’t work. Well, it does chime, but it dies once the OS has loaded.

Posted by: croissantking on 2025-11-01 07:15:40 Swapped out the audio amp and the sound is fixed! This board is REPAIRED.

Posted by: jmacz on 2025-11-01 07:38:14 So awesome!! and those traces are so tiny! Congrats! 👏

Posted by: Callan on 2025-11-01 07:49:18 Congrats on getting this one fixed! I've had nothing but headaches working on these boards, so I know what you went through to fix it. Amazing job!

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