68kMLA Classic Interface
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| Found a vintage Mac Plus, but it's got a "Sad Mac" and a weird wiring job inside. Any ideas? | |
| Posted by: Huxley on 2019-05-11 15:25:07 As I shared a couple days ago in the Conquests thread, I was lucky enough to find a Macintosh Plus with keyboard and mouse for $15. The seller did inform me that it beeps on power-up, but he never saw anything onscreen. I've just gotten it home and tried it out. I find that it does indeed beep when I hit the power switch, and I do get an image on the display (though the image flickers like mad if the Mac or the table is moved / bumped / jostled at all), but unfortunately it's only showing me a Sad Mac with an error code "0102D1." Even more weirdly, on the underside of the motherboard is what looks to be a "DIY" patch-cable, linking one IC to another. Here's an album with some pics, including the patch-job I found. I'd really appreciate any tips or suggestions - I'd love to get this machine back to life! Update: I carefully reseated both ROM chips and cleaned / reseated the RAM but it hasn't made any difference - the machine still Sad Macs upon boot 🙁 | |
| Posted by: Huxley on 2019-05-11 16:51:52 Made a quick video of the two issues I'm seeing - I hope this helps clarify what's going on! | |
| Posted by: mattsoft on 2019-05-11 18:54:38 I had a similar problem on a Plus and it was a cold solder joint on the analog board where the power molex connects. I simply reflowed the solder on the analog board for the molex connector and all was good. YMMV. 🙂 | |
| Posted by: unity on 2019-05-11 18:58:17 And dont forget to reflow the solder on the mobo connector too.  | |
| Posted by: dochilli on 2019-05-14 03:52:18 The error code 01 means that there is a problem with reading the ROM. The 02D1 is meaningless. Perhaps you can change the ROM. As far as I know you can burn a new with 27C512 Eproms. https://www.nightfallcrew.com/25/04/2014/macintosh-plus-sad-face-repair/ | |
| Posted by: Huxley on 2019-05-15 09:21:28 Quick update: a lovely / kind person on Reddit has burned some fresh ROM chips for me, and even threw in a MacOS 6.0.x boot disk for me to use during testing, and they even refused any payment for all of this. The package should arrive sometime in the next couple days - if the Mac boots nicely with the new ROM's, I'll definitely move on to troubleshooting the analog board. As someone with super basic / rudimentary soldering skills (and no fancy tools beyond a $15 Amazon soldering kit), are there any specific tips / tricks / tutorials you guys would recommend? I'm starting to look around on YouTube for tips (there are a lot!) and feeling a little overwhelmed... | |
Posted by: dcr on 2019-05-15 09:48:11As someone with super basic / rudimentary soldering skills (and no fancy tools beyond a $15 Amazon soldering kit), are there any specific tips / tricks / tutorials you guys would recommend? I'm starting to look around on YouTube for tips (there are a lot!) and feeling a little overwhelmed...There was a useful video on YouTube someone posted last year I think that was basically an introduction to soldering that had a lot of good information in it. I don't remember the thread, but hopefully someone will remember the thread or video and post a link. The other thing I would recommend is to buy some inexpensive electronics kits. I've gotten ones from AdaFruit, but SparkFun and many others have them. That gives you good practice without risking screwing up a Mac, and you can instantly see results. It can help build skill and confidence. Does your soldering kit include a solder sucker? If not, get one. I don't know how I got along without one. | |
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