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croissantking's repair journey
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!
Posted by: croissantking on 2026-03-03 14:48:52 I bumped a couple of PowerBook RAM cards to max capacity, the first being a partially populated ‘death chime’ card suitable for a 165c/180c. Well, I did my thing and found the bad chip, then put all the spare chips back on one bank at a time after testing them first. Here’s the finished result, a lovely fully working 10MB card: It has three buffer chips onboard which my other three 10MB cards not have. And interestingly, it’s the only one that fully works in a ‘fussy’ PB180 daughtercard that usually has stability problems when maxed out with RAM. I also maxed out this (formerly 8MB) PowerBook 500 series RAM card to 32MB. It replaces another which was collateral during my quest to build a 48MB card. Thanks to @imactheknife for the bits 🙂
Posted by: Durosity on 2026-03-03 15:26:25 Oh fun, I’d love to max out a board for my 550c prototype someday!
Posted by: imactheknife on 2026-03-05 15:42:17 I bumped a couple of PowerBook RAM cards to max capacity, the first being a partially populated ‘death chime’ card suitable for a 165c/180c. View attachment 96299 Well, I did my thing and found the bad chip, then put all the spare chips back on one bank at a time after testing them first. Here’s the finished result, a lovely fully working 10MB card: View attachment 96300 It has three buffer chips onboard which my other three 10MB cards not have. And interestingly, it’s the only one that fully works in a ‘fussy’ PB180 daughtercard that usually has stability problems when maxed out with RAM. I also maxed out this (formerly 8MB) PowerBook 500 series RAM card to 32MB. It replaces another which was collateral during my quest to build a 48MB card. View attachment 96301 Thanks to @imactheknife for the bits 🙂 Excellent!! Good job! Glad you got it functional🙂
Posted by: croissantking on 2026-03-14 14:16:39 I fixed up a broken Micron Xceed SE/306-48 video card this weekend - turned out to be a trio of faulty GAL chips. Full journey documented here.
Posted by: jmacz on 2026-03-14 20:54:40 👏
Posted by: croissantking on 2026-06-09 06:44:06 I picked up a 30 pack of Metristak connectors from The Connector People that will eventually be used in new-build 500 series CPU cards. With many thanks to @Callan for proxy shipping them to me.
Posted by: Durosity on 2026-06-09 06:54:53 Great.. ship some to Newer so they can build that mythical G3 upgrade card for the 500 series!
Posted by: croissantking on 2026-06-09 06:56:21 Great.. ship some to Newer so they can build that mythical G3 upgrade card for the 500 series! Hah. I'm hoping to reverse engineer a G3 upgrade for a PB1400 (when I get one) and do this myself.
Posted by: Durosity on 2026-06-09 07:02:50 Hah. I'm hoping to reverse engineer a G3 upgrade for a PB1400 (when I get one) and do this myself. Ya know, I had a sneaky suspicion that was why you were after a G3 card for a 1400. If that can happen that would be AMAZING.
Posted by: mg.man on 2026-06-09 07:19:36 I'm hoping to reverse engineer a G3 upgrade for a PB1400 (when I get one) so... you're looking for one?
Posted by: croissantking on 2026-06-09 07:22:38 so... you're looking for one? I am, but it needs to be one of the ones with an FPGA onboard, which means Interware/Vimage. The Newer and Sonnet ones have a CPLD which is very likely copy protected.
Posted by: mg.man on 2026-06-09 07:26:35 it needs to be one of the ones with an FPGA onboard, which means Interware/Vimage I have two Interware ones... I think one might have a borked FPGA tho... I'll try to have a look when I get some time.🤞
Posted by: croissantking on 2026-06-09 08:24:36 I have two Interware ones... I think one might have a borked FPGA tho... I'll try to have a look when I get some time.🤞 Cool stuff.
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