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pinto_guy

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    Palo Alo, CA

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  1. pinto_guy

    Horizontal line on Mac Classic

    Sorry bibilit, I realize that my thread is somewhat confusing. When I tested the AB, I was using a good LB from another Classic. Once the AB was OK, I put the original LB in, and this is when I lost the chime/bong and the checkerboard issue came up. Sorry for the confusion. So I do not have the bong any longer. I could probably easily scope the reset and data lines. Can you please let me know where to get them ?
  2. pinto_guy

    Horizontal line on Mac Classic

    Yes, I swapped the ROM chip with one from a good board, but no effect. I also put the LB in a wash cycle in the dishwasher, and I get the same pattern.
  3. pinto_guy

    Horizontal line on Mac Classic

    Yes LaPorta, the LB was recapped. How do you reseat the RAM chips ? Looks like the internal RAM chips are soldered on. Interesting that you mention the RAM though, as I notice that the checkerboard pattern is different if I do not insert the external RAM module (left image), or even with two different modules (right 2 images). I'm hoping this can help me, but can't figure out what to do next.
  4. pinto_guy

    Horizontal line on Mac Classic

    Update today. I have received the TEA2037A, and swapped it. Alas, no luck and the horizontal line was still there. I suspected that the flyback transformer could be the culprit, so I swapped it with one taken from a good board. No luck either. Upon examining the board one last time and slowly losing hope, I discovered another Nichicon "brown cap" which I hadn't replaced. It's CP11 - 220uF, kinda on its own, near the flyback. It was a bit sticky with lint attached to it, usually a sign of leaky goo (photo) So I changed it, and the screen all the sudden showed sign of life. However, I now have the infamous checkerboard pattern (photo) !! I checked and rechecked all of the Tantalum caps which I had replaced earlier on the LB, thinking that they were somehow responsible for the horizontal line. I checked the traces and all the usual suspects, but no success. Another LB from a working Classic makes the system boots OK, so I know the AB is OK. Have any of you seen this pattern on a Classic ?
  5. pinto_guy

    Horizontal line on Mac Classic

    Thanks dochilli. Will try and replace. Can the flyback transformer somehow be involved too ?
  6. pinto_guy

    The cast of characters in the Mac SE Easter Egg

    Yes joshc, I'm collecting interesting tidbits from the people on the photos, and will report. Thanks Dog Cow for the mention of the QuickTime slideshow. I couldn't find much about this on line. Is this available on the Compact Macs ?
  7. pinto_guy

    SE/30 repair help

    Yes, AFAIK, the screens are the same between an SE and an SE/30
  8. pinto_guy

    The cast of characters in the Mac SE Easter Egg

    Update: I was able to contact Marjory Kaptanoglu (second image). She has changed career and is now a novelist. Her website is here in case you're interested. She was able to identify one more person as Brian McGhie (first photo, second from top left). By the way marcelv, I sent you a PM. Did you get it ? If you could help me with my Mac Classic issue, that would be great too
  9. pinto_guy

    Horizontal line on Mac Classic

    I'm hitting my head against the wall on this one. The system boots (firm bong), but the screen only displays a half horizontal line (photo below). I have replaced all the usual suspects on the AB (brown caps) and voltages are OK (5 and 12V right on the money). I checked the H and V sweep voltages with a scope, and they are both a bit funky (see V sweep below) when I compare to a "good" board, although I am admittedly a novice at troubleshooting video issues. Is there a component that could be responsible for both H and V sweep to be out of whack ? And why do I not see any V sweep on the screen when V sweep voltage shows a signal ? By the way, the problem is very similar to the one on this 2018 post, which unfortunately does not have a conclusive resolution.
  10. pinto_guy

    The cast of characters in the Mac SE Easter Egg

    Awesome, thanks marcelv. I didn't not expect to make such rapid progress in so little time. I updated the photo accordingly. If you could double check the names, that would be great. I will reach out to some of these people, if I can contact them, to try and fill in the blanks. Thanks again !
  11. As I was pulling another Mac Classic from my collection to repair, I noticed a faint writing on it. Upon further inspection, here is what I found (photo attached). I usually start my repairs with a thorough clean of the case, but I think I'll leave this charming graffiti. I might even retr0brite the case to improve the contrast. I wonder whether Anne and Rog ended up connecting...
  12. I was recently in contact with one of the early engineers on the Mac team and we discussed the Easter Egg on the Mac SE (set of 4 images that flash on the screen after typing "G 41D89A" in debugger mode). I asked him if he could identify some of the people on them, and he knew two of them. In the picture attached, he recognized (1) Bob Bailey (a Chip Designer) and (2) Brian Howard (Employee #32 on the Mac team). I was able to easily find bios about both of them. I'd like to complete the line-up if possible. Would any of you on this forum be able to help me in this historical mission ?
  13. pinto_guy

    Zip Drive

    Thanks chu-oh. I'll give it a try too.
  14. pinto_guy

    Zip Drive

    Just bought a G4 iBook from Craigslist for $25, running 10.4.11, Will pick it up tomorrow. So I should be all set. Thanks all.
  15. pinto_guy

    Zip Drive

    Thanks. Yeah, I'm pretty sure I read somewhere that High Sierra still had full HFS legacy R/W support, but I also read otherwise, including in this forum. It clearly still offers read access tough. And yes, I'm talking about HFS, not HFS+ Has anyone have any luck with FuseHFS ?
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