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The heck? Are you the guy who designed these? If so, kudos! If not, thank you very much for pointing me in their direction! This is fantastic and serves as a good time to update with progress. So, the PSU is sidelined for the moment. It's not dead dead, just "TV" dead (it'll probably be back)...

Geez, dude - more than anything, glad to hear you're doing okay! R29 is functionally useless; I've replaced it with another pot with the same results - no adjustment to output voltage whatsoever. I'm combing through LisaList for info on U3; there's only one left on eBay, so I may go ahead and...

Surely! I'll grab the project list from Mouser in a bit. The card edge connector was off of a Pac-Man arcade PCB filter board I had lying around, but they can be had for about $6 from Mouser as well (22/44 pin EDAC brand).

Okay, the results are in! I assembled a load tester (pics below) and got the following voltages before the fuse blew again: +5v rail: +8v +12v rail: +18v +33v rail: +53v -5v rail: -5v (one success, at least) -12v rail: -18v +5 standby: +5v (5.5, but, eh) The same two caps puff up after a very...

Signs of life... sort of. I recapped the PSU and checked the six main transistors. Mostly satisfied with the results, I checked everything for glaring issues, dropped the PSU back in its cage, and fired everything up... to hear the CRT coming to life and see the power indicator light on the...

Alrighty - PSU images attached!

Yeah, that was my worry - the fuse was just the iceberg for something else inside the PSU. Fortunately, it doesn't blow after being powered on now, though. Thank you for taking a look at your PSU! I'll grab some pictures of mine in a moment after I finish inhaling lunch.

As for the PSU, it makes the familiar chirping when attempting to power on the Lisa (the I/O board is removed for cleaning, but I wanted to verify the machine would even power on first), so I've been going over everything I can think to. Using the thread by @rdmark as a guide, the six main...

Forgot to post this earlier and already have a couple of updates! First, I have a keyboard on the way, so yay! Second, I've had a chance to clean this thing up quite a bit. the I/O board pins are fine and a fiberglass brush did indeed take care of them, much to my surprise. There are some...

Going to try to keep this a cross-post with 68KMLA, but I've managed to acquire a Lisa 2 and will detail my repair endeavors here... I was cruising Facebook marketplace a couple weekends ago and came across something I never thought I'd see an ad for on there: a Lisa 2. The asking price was...

Good to know it can "boot" to some some extent for testing. That alone will provide a world of info moving forward - thanks! As far as it being spread across other schematics, I think you're right. I may sit down and tone out the motherboard before I do anything further. I've got both EMI...

Thanks! I picked up a replacement card edge connecter from your eBay link above and picked up some ICs from Mouser to replace ones that at least look toasted, so I should be good there. I had to order the EMI filters from DigiKey, as Mouser is now totally out of them, so no big deal there...

@rdmark Would you happen to have a BOM or list of vendors you got ICs from? Figured I'd ask here first rather than just duplicate work that may already have been done.

@rdmark I just acquired a Lisa 2 in a near identical state. The COP421 looks like it survived the battery leak unscathed, so I'm hopeful for this thing's future. This thread will be an invaluable repair guide to reference as I get this thing shored up - thank you so very much for documenting...

Depends on a handful of factors, but, one of the bigger reasons folks will encounter bad 3.5" floppies is that as they were waning in popularity they began to be manufactured at lower and lower qualities. I have a set of floppies for MacDraw that were kept in a craptacular environment for years...

Excellent news! I'm so glad it was just the CPU needing to be reseated. If you'd like, DM me an address to ship to and I'll send some spare floppies your way.

It's entirely possible the the 486 is just toast. That card is basically a run-of-the-mill PC; it should POST and give you the same basic info on screen as any other contemporary machine. That it's not even getting there is pointing more and more toward a CPU issue, just as it would in a PC...

Attached is a zip file with the two setup disks (img format) I used to setup my 6100, along with another zip file containing the SB16 drivers (I've never had a disk image for that, just the files since it's all DOS-based). Somewhere I had a fourth disk with, I think, some additional drivers for...

No video with a "PC is booting" message that never progresses means the PC isn't POSTing. Under normal circumstances, you should be able to immediately switch over to the PC and see the typical RAM test you would expect from contemporary BIOSes. Make sure your RAM is seated correctly and that...

Congratulations! Not only do you have a DOS card, you also have the proprietary connector cable for it (which is arguably worth more than the card itself at this point)! To answer your last question first - that smaller PCB screwed down to the larger one is a SoundBlaster card, which means you...