68kMLA Classic Interface
This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.
| Click here to select a new forum. | |
| Well it used to work: 128k woes | |
| Posted by: Online persona on 2021-10-02 22:57:11 Hi everyone. So my recently acquired 128k with the 512k socketed upgrade won't boot now.  I had the caps replaced and upon return I get no bong on power up and a screen of vertical lines. Installed a Plus logic board and it boots fine. So far I've reseated all the RAM chips. Cleaned the ROM pins and reseated and reseated that chip that controls the memory upgrade. Still the same problem. Any ideas? I'm guessing memory problem based on the Larry Pina books, but I'm just an amateur. | |
| Posted by: Online persona on 2021-10-04 22:27:09 More troubleshooting: Swapped in the ROM chips from a working Mac Plus. Got the error code 02002 | |
| Posted by: Online persona on 2021-10-04 22:28:11 Oh yeah, one capacitor was backwards. I fixed that. Still the same. | |
| Posted by: cheesestraws on 2021-10-05 01:41:45 For clarity, 02002 is a sad mac code? Per https://udcf.gla.ac.uk/~gwm1h/Error_Codes/Sad_Mac_Codes.html, that points to the ram chip in position F7... edit: apparently I can't read, F6... | |
| Posted by: Online persona on 2021-10-05 18:59:50 Hmm, would it boot if I remove F6? | |
| Posted by: LaPorta on 2021-10-05 19:02:16 Who put these in that installed one backwards? Did you ask them if they touched anything else? Do you have an ESR meter to verify that the caps are in good shape? | |
| Posted by: Online persona on 2021-10-05 19:43:12 I just have a multimeter, will that work to test the caps? | |
| Posted by: cheesestraws on 2021-10-06 02:43:02 I'd try swapping the memory chips at F6 and F7, since they're socketed, and see if the error moves. If it does, it's the chip; if it doesn't, it's something else, perhaps the traces to the chip? | |
| Posted by: Online persona on 2021-10-06 21:27:43 I'll give that a try. | |
| Posted by: Online persona on 2021-10-09 15:39:04 Switched F6 and F7, installed my Plus ROMS and it booted. Put the original ROMS back in and the same problem. Tried it a couple more times and it seems that I've got bad original ROM or ROMS. | |
| Posted by: mg.man on 2021-10-09 15:41:33 Could be bad ROM(s)... worth checking the pins on the originals to make sure they are clean and "crud"-free... Sounds like progress tho! | |
| Posted by: cheesestraws on 2021-10-09 16:06:58 ROMs do sometimes go bad. It's not particularly common—not like RAM going bad, which happens all the time—but not particularly rare either. But so do cruddy legs on the chips, so as @mg.man says, check those before despairing of the ROMs. 🙂 | |
| Posted by: Online persona on 2021-10-09 22:31:23 I've scrubbed the pins, they were tarnished a lot. Still no go. In good news I got the 400k drive working! I bought a NOS felt pad for the drive off ebay, installed it, and now it works well. The old pad was almost totally gone. | |
| Posted by: dochilli on 2021-10-12 04:05:21 ROMs can be burnt into Eproms. Here is an instruction for a Plus: 
Create Macintosh Plus ROMsCreate Macintosh Plus ROMs: This Instructable will guide you through the process of "ripping" EPROM images from from your Macintosh Plus ROM chips and (or) "burning" the images to new chips. The process will basically be performed twice to create both "hi" and "lo" ROM chips f…
www.instructables.com
For a 128 27C256 Eproms could work. 
Mac 512k error code 014120Hi, I have recently been charged with repairing a Mac512k. On powering up i get a beep followed by the 'Sad Mac' and an error 014120 I think this is a ROM issue, is this correct? There is another site "http://members.tripod.com/elfen_magix/sadcodes.html" which suggests that this is...
forums.macrumors.com
| |
| Posted by: Online persona on 2021-10-13 22:15:15 That's interesting info, but I'm afraid it's above my pay grade to implement. I do have a set of ROMS on the way from ebay. | |
| Posted by: dochilli on 2021-10-14 00:28:01 A TL866II Plus Programmer is about 70 Euros. If you burn your own ROMs you can play with some extensions. Mac ROM-inator I Kit | Big Mess o' WiresThe rominator needs some soldering, but then you can use a ROM disk or an alternate start beep. | |
Posted by: Online persona on 2021-10-24 15:55:57 New ROMS installed and all is well. Boots and runs fine. Floppy Emu has a version of system 1! Fun times. My first Macintosh experience was in 1985 on a similar machine at work. It was an astounding revelation, and this brings all those memories back. | |
| Posted by: cheesestraws on 2021-10-24 16:25:49 Wooo! Nice to see this all working again. | |
| 1 |