I've had a lovely evening tinkering with my Lisa 2/10. I was playing around with using BLU from my ESProFile (connected to the internal Parallel port) and seeing if I could get it to recognize my 5MB ProFile connected to the troublesome 2-Port Parallel card.
After reconnecting the ProFile and letting it spin up to "Ready" status, I powered on the Lisa. Instead of its usual boot routine, I heard a rapid series of crackling / popping sounds from the speaker. A moment later I saw/smelled a puff of acrid smoke from the rear of the machine (I saw it through the empty drive bay), and at the same time, the display showed a rapidly-shifting checkerboard pattern. I immediately pulled the power cord and let the machine cool off. I also pulled out the card cage from the rear and at least initially I don't see any obvious scorch marks.
Powering the machine back on now just shows the same flashing checkerboard pattern for a few seconds before everything goes dark. Here's a short clip of what I see on the screen. (https://imgur.com/a/lisa-checkerboard-6j7hss1)
I'm just crushed, and I honestly can't tell if I did something wrong, or if it's just some old part that finally failed. Anyone have any suggestions on what I should do next?
Sorry to hear about this failure! Don't beat yourself up too much, it's a Lisa, these things happen.
Ordinarily smoke and cracking sounds owe to RIFA capacitors blowing in the PSU, but that doesn't usually affect the picture, and it's the wrong side of the machine if you saw smoke through the drive bay. That's the side that has the expansion bay and (an edge portion of) the logic cards.
The fact that it still powers on (presumably when you press the power button) and gives you a raster is a good sign and means that probably you haven't e.g. experienced the +12V rail shorting onto the +5V rail and blowing all of your chips to smithereens (which to be clear I have never heard of happening). In other words, this can almost certainly be fixed.
Since you saw smoke, that means that you should be able to find a component somewhere that looks distressed. You haven't spotted it yet, but I think you should keep looking. It may be just a single component like an IC that has a scorch mark on it somewhere. Consider also using your nose (seriously!).
Your parallel port card has been giving you trouble. What happens if you take it out and power on the computer? The card also has a plastic cover, which may mean some damage is concealed. Either way, you'll probably want to leave it out when you're troubleshooting this problem (and disconnect other things too, like the ESProFile and maybe also the Widget and the floppy drive). It narrows things down.
If the Lisa still doesn't work, then the troubleshooting journey begins. Step 1 in my opinion is always to check voltages (although actually I would still keep looking for the broken component for a while before doing that). You will want to find some way to access and monitor the voltage rails as you attempt to power on the computer, particularly the +5V rail. (The power connector going to the Widget is a good place to do this.) If it isn't close to +5V, then that's likely to be the issue! If it is, we'll think of something else.
Good luck!
(PS: Imgur geoblocks the entire UK, so I can't see your video from here, unfortunately!)
Thanks for the calm and reassuring reply, @stepleton - I appreciate it. I'm super bummed but as you noted, these are extremely complex machines with countless components that are probably 2X-4X beyond their expected service lives.
A couple quick notes:
- Good to know re: Imgur - I'll keep that in mind going forward!
I'll try attaching the clip to this reply, hopefully it's not too large to work. Turns out this board doesn't allow video attachments, so I uploaded it as a YouTube (very) Short (https://youtube.com/shorts/9aeLn-_QqSg?feature=share) - I did see the smoke through the drive cage area but at the time this happened, I had the drive cage fully removed, so I can't really say with certainty that it came from that side of the machine
- Great suggestions re: giving the cards a closer expansion and testing again with the Parallel card removed. I'll try that later today!
I'll update again once I have something worth sharing.
EDIT: I just saw a couple posts from Ried referencing similar painful outcomes due to a card shifting and shorting other components. Given that I experienced this failure immediately after plugging the ProFile back into the Parallel card, I'm suspicious that maybe I did something similar...
Quote from: Huxley on January 22, 2026, 09:54:18 AMEDIT: I just saw a couple posts from Ried referencing similar painful outcomes due to a card shifting and shorting other components. Given that I experienced this failure immediately after plugging the ProFile back into the Parallel card, I'm suspicious that maybe I did something similar...
I know a couple other people whose Lisas have also been fried due to a shifted expansion card, so this is what I'm guessing too. Especially if the card doesn't have the card stop on it, but this can also still happen even if it does have the stop.
I am back with a genuinely shocking + delightful update: Lisa lives!
As Stapleton suggested, I pulled the Parallel card out and tried again, and to my utter amazement she fired right up as though nothing was ever wrong in the first place. Incredible!
The Parallel card does have a pretty strong smoke smell, but I really can't see any obvious signs of damage. I'll attach a high-res photo of the Parallel card - perhaps someone with more electronics repair experience will spot something I'm missing?
On a very related note... anyone have a spare Parallel card they'd like to sell? ;)
EDIT: a kind person on Discord pointed out that the 74LC00 chip in position C12 (lower right corner) appears to have burst. I've ordered a replacement for a few bucks from eBay - fingers crossed!
QuoteI am back with a genuinely shocking + delightful update: Lisa lives!
...obvious signs of damage
Congrats!
The hole by the card edge fingers is where a mechanical stop should have been attached. If you attach one (strongly recommended), make sure it does not short out any of the gold fingers.
It looks to me that this is a reproduction rather than an original, but even an original could be missing the stop, so I suppose this is a caution to everyone to look over a new acquisition carefully.
It looks like the 74LS00 near C12 has a bubble on the surface, if so (rather than something stuck to it), that may indicate one of the points of failure (there could be more). Since it is in a socket (sometimes a major benefit of some reproductions!), you could remove it and sniff it separately.
Congratulations! This is good news.
You could replace the 2-port card entirely, but with every single chip socketed like this, you might have a great opportunity on your hands to learn and do some electronics troubleshooting at the component level, without all the hassle of soldering. (I'm assuming this isn't something you've done much of; I hope this is correct, and if not my apologies!) Obviously replacing the 'LS00 is necessary, but this might only bring you back to the point where you were before: a parallel port card that doesn't seem to work.
If you're interested, we could work with you as you go. If the problem really lies on the card (and it may not: could your Lisa motherboard have a problem? did the card come with the computer?), chances are that just replacing one or two chips will be all you have to do. Figuring out a fix like that can be mighty satisfying.
If it were just me talking to you (and maybe it is --- I can't volunteer others on their behalf!), I'd be inclined to go ahead by asking leading questions that might take you down roads I would take if I were troubleshooting the card. The hope would be that this could build some habits of diagnostic thinking that you could apply later. Of course I might also just embarrass myself: there are much better troubleshooters on this forum than me!
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But before any of that: I think we should make certain that your card isn't going to cause trouble on the power rails even when you stick the card in correctly. If you have a multimeter, I would measure the resistance between the power pins on the card and the ground pins. PDF page 73 of the Hardware Manual (http://www.bitsavers.org/pdf/apple/lisa/hardware/Lisa_Hardware_Manual_Sep82.pdf) shows you which pins carry power (note +5V, +12V, -5V, -12V, and +5V Stdby) and where to find ground (or "Digital Ground").
The card only uses +5V. If there is any less-than-infinite-basically resistance between any other power pin and ground, then that's not supposed to be there!
If the +5V to ground resistance measures quite low (perhaps in the teens of ohms or below), then something is awry, and we should work out what's providing such an easy path for current to flow from +5V to ground.
But if it's higher than that, then you probably won't have to worry about smoke again, provided the card always goes back in the slot correctly!
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Now for a first leading question. Here is the schematic for the parallel port card. (http://www.bitsavers.org/pdf/apple/lisa/hardware/Lisa_Parallel_Intf/050-4027-A_Parallel.pdf) It will look very complicated if you're not used to looking at these things very much. But for now we don't need to understand it. I want to ask: there are 15 chips on this card (and five resistor packs, which look like chips but are just a bunch of resistors in a single package). Why did the 74LS00 at position 2F explode and not one of the other chips?
Note the PDF actually contains two copies of the same schematic, and each copy contains two very similar-looking circuits, because this is a two-port card. But the 74LS00, also called U2F because "U" means "microchip" and 2F is the location, only appears on the first sheet of each copy. It actually appears in multiple places for reasons we don't need to go into now. But observe what the U2F symbols are connected to... and now look back at the locations of all the power pins from the Hardware Manual. Why did U2F suffer so much?
This is such a lovely and generous reply to this thread. Thank you for providing so much encouragement and knowledge here!
For context, this Lisa is the latest addition to The Retro Roadshow (https://www.retroroadshow.org), the pop-up museum my wife and I created. We've just been booked for 2 (possibly 3) events this spring with an Apple theme, including one at a *very* prestigious venue. Having a functional Lisa to exhibit and share alongside some of our other notable Apple (and Apple-related) systems is obviously a pretty big deal. I'll definitely revisit this Parallel card but for now I'm just very excited that the machine itself is functional enough to exhibit!
One more detail before I forget: I did get confirmation that this Parallel card is a modern replica which was put together by the previous owner of this Lisa, and they apparently had some issues with it during the initial build that necessitated un-soldering and redoing the whole thing at least once. Good info to know!
Ah yes, that's really good to know :-)
Someday stick the solder side into a flatbed scanner (or just snap a photo) so that we can have a squiz...
Huxley,
If you want a replacement Dual Par Card, PM me and I will hook you up.
I put together some blue boards to demo the adapter I designed for the ESProfile at VCF midwest last fall and I still have a few around. The adapter allows you to connect two ESProfiles to the Dual Par Card at the same time.
Rick
Quote from: stepleton on January 23, 2026, 06:21:27 PMAh yes, that's really good to know :-)
Someday stick the solder side into a flatbed scanner (or just snap a photo) so that we can have a squiz...
Will do!
Quote from: Lisa2 on January 23, 2026, 07:23:52 PMHuxley,
If you want a replacement Dual Par Card, PM me and I will hook you up.
I put together some blue boards to demo the adapter I designed for the ESProfile at VCF midwest last fall and I still have a few around. The adapter allows you to connect two ESProfiles to the Dual Par Card at the same time.
Rick
Oh wow, that's amazing! I'll PM you now :D