Was watching this video when visiting my parents.. then dad peeks over my shoulder: 'Hey.. I got one of those down at the server room at work, want it?' Suddenly i have a Compaq Portable that I have to clean up.
Sell it, or give it away to this guy. I worked with plenty of this junk as a kid, it is perplexing to me why anybody want to collect it, but I am an engineer - we build better stuff today. I think you're going to be disappointed. It belongs on a museum, and I don't think it's useful for anything when you can simulate it at the gate level today - and you probably won't even do that ever.
@@fuzzywzhe Why do people collect anything at all? Why do we have emotional attachment to inanimate objects? Doesn't matter if we can emulate it to the molecular level.
How funny. Someone gave me one of these, too. And it's in the same state as David's. Fan comes on, but no display and no activity. I suspect a bad power supply.
@@leandrotami I didn't mean to sound critical, I just don't understand why people collect this stuff. If I want to relive an experience from my childhood with a computer, it's the experience of using the machine, and simulation is 100% accurate with the machines I used. I would never own a C=64 again simply because compared to the machine I have today, it's a waste of electricity to even turn it on. My VASTLY more powerful computer can simulate 20 of them running at the same time on 1 machine, and use less power. But it's fine if you use actual hardware, of course. I just don't understand it.
I'm so glad there are people like you out there keeping this old stuff alive. I feel like you are doing a valuable service for the world by keeping this stuff in living memory.
I'm waiting for him to demonstrate an Babbage Machine or an Astrolabe. How about an internal combustion engine? He's just demonstrating what he grew up with, he has no understanding what that's been based upon. Have him demonstrate a radio built entirely with tubes, explaining how the tubes work. They are similar to transistors, but I bet he has no idea how they function.
I thought about starting a thread about this but didn't want to come off as a know it all so I'll just post it here. Yeah, I was expecting that too. As soon as I saw the blinking LED I thought "yep, shorted capacitor somewhere." At least blowing it up allows one to find the bad one, LOL.
As someone who enjoys the restoration process, but is not much of historian or expert of the computers of old, I'm very impressed with the design, with the modular parts, and the rubber mounts!
Seannyyx I still kind of wonder what that guy's deal was, was he just a wierdo who really wanted an old leather handle for some reason, or was he a legit amateur leatherworker who bit off more than he could chew and ghosted David because he messed the handle up?
5:38 "oh sure yeah don't worry everything will be fine" yeah famous last words, huh? :P at least it all worked out in the end. looking forward to part 2, these repair videos are always fun to watch!
I have one of these! Bought it for $25 at a garage sale in '06. Perfectly working with a 20mb HDD(full of old psych patient records) and a full set of software & even a printer too. The software & printer were sadly lost over multiple moves in the last 14 years but I still have the Portable in storage. Amazing system and I actually used it for a while for writing.
"So I went down to my friends house who had this random, defunct, wort hless1980's electronic board laying around for years that was just the thing I needed" You have some awesome, but odd friends.
@@DalekCraft me too lol.. trouble is I now need a bigger display case. I seem to have filled this one up, barely room for myself, daughter and the three cats. :D Only joking, always room for more useless rubbish I hang onto incase I may need it lol.. I swear I have a draw FULL of old phone chargers, pc cables going back YEARS, and printer cables and related parafunalia.. ink etc lol.
Looking forward to the Part 2! I actually went through about this same adventure with my Compaq Portable. It turns out that the power supply is smart and if too much current is drawn, it will shut down to prevent damage. Those darn tantalum's are a huge problem in electronics this age. I ended up having one of them on the motherboard and one on the video card that were shorted. Found them by pulling the motherboard and testing the power rails using a bench power supply. Turn it on briefly and use a thermal camera to look for hot spots which show up pretty fast. Pull and replace the cap and fixed! I think my floppy controller had a bad can oscillator on it too which seemed like an odd failure, but was also easily to replace. The AC filter smoked not long after playing with it and was to be expected according to many who were giving me advice. This got it booting, both floppy drives worked great right off the bad. Keyboard problems were the next thing I found with the bad foams - replaced those. The last problem was that some video characters would inadvertently change on occasion. Used a Hakko FR300 to remove DRAM's from the memory board and replaced them and solved that. These things can be quite a bit of work to get working, but they are really cool machines. I think you can use a ctrl-alt combination to switch between a true mono mode and cga mode. Maybe ctrl-alt-< and ctrl-alt-> or something like that.
Brings back so many memories. Staying up all night downloading games and apps from local BBS sites at 2400 baud, around 220 bytes per second with the zmodem protocol if I remember correctly. Great machine.
You had a 2400 baud modem? PSHAW! My first modem was a 300 baud manually switched Radio Shack model. It was a couple of years before I traded up to a genuine Hayes 2400 baud unit.
Very enjoyable video, as always. I don't really understand anything about programming or electronics, and I was growing up around more contemporary devices, but I still like to watch you work on these machines, and learn a bit.
I had one of these when I was a young teen. It was hopelessly obsolete when I got it, but it had one advantage, my parents didn't know that it functioned and the modem worked. In a nutshell, I would use it to dial to BBSes at night when I was grounded from the family computer. Nothing like an 8" greenscale screen and a 2400 baud modem. Ran MS-DOS 3.3. Mine didn't have a hard disk, just dual 5.25" floppy drives.
Yeah, BBS - Bulletin Board system is very much like a web page but run by one person or company and you connect to it by dialling a specific phone number. I used some around 1993 and 1994 (downloaded shareware games from them mostly), right when the internet was starting, but the internet very quickly made them obsolete. Though... You could still find a decent number of them up into 1998 or so... And even to this day there are still a few random holdouts. The thing about a BBS is that anyone with a computer, a few modems and a few phone lines could technically set one up. Nowadays I suppose even phone lines themselves are becoming borderline obsolete technology though. So I suspect BBS will die a final death whenever fixed line phones do.
There's still quite a few BBS'es out there, but nowadays most are set up to be connected to via telnet. No more waiting an hour for a single jpeg to download via X/Y/ZModem!
@Samar Nadra: 14400? How luxurious. Try 2400 baud. The city library system's BBS also had a Usenet portal, so I was able to do newsgroups, albeit quite slowly. Had to be judicious as to what conversation threads I viewed.
@Kuralthys: yep. Bulletin Board Systems. Basically good for forums, e-mail (including cross-BBS e-mail with Fidonet and one's offlline mail reader like Bluewave), and some limited file transfer and shareware distribution. Some BBSes had multiple phone lines and allowed for teleconferencing, but because of the popularity of that feature those BBSes were either congested or cost money to use.
the video lists the music used at the end. Smooth Bed 2 Mr.Drum & Bass 1 The Last Goddess - Carmen's Theme One or more of those are from someone named Anders Enger Jensen. And none of them seem to be part of the music collections offerd on 8-bit guy's site. Ok, a quick search pulled up Jensen's RUclips channel on the last song: ruclips.net/video/X-ZMgflCu98/видео.html Sounds like what 8bit was using for the drive disassembly.
Glad to see one of these again. I hauled one of these "portable" machines with me when traveling on business to Mexico in the early 1990’s. "Loved" taking it through airports and on to planes.
I don't have much interest in retro-computing nor the resources to store old stuff but your videos are great troubleshooting training material. Learned a lot about how to troubleshoot from watching you. Thank you such much 8-Bit Guy.
Colby Pacholko Unlike eclectic boom I know I will do something stupid but nah who cares let me touch..... Me: JUMPS OF THE CHAIR ME: Fucking hell Electro boom: FUCKING HELL
Great video! I have never used an old Compaq. But I love seeing your diagnostic process / walkthrough and all your troubleshooting, trial and error. While others may breeze through such things with montages, I appreciate that you documented every step of the way.
Geez, I’m feeling old right now. I was there when these were the best thing! I used to service these and many other computers of similar vintage. Olivetti, Compaq, Alpha Micro, IBM. Back in the day when businesses used to call service companies to fix things. Reseating chips, cleaning out the dust, cleaning edge connectors, disassembling keyboards cleaning and fixing them. Chasing logic circuits to find the one chip that was dead was a passion and very rewarding!
Wow, does that bring back memories. Through my late father, my sister and I gained exposure to a variety of computers in the late 70s/early-mid 80s, more so than many of our peers. Dad was a Financial Manager in Forestry R&D for Weyerhaesuer, and not only did we get to interact with the DEC VAX mainframes in the basement with the communal Courier terminals just a few yards from his office, but he regularly brought home computers on extended loan. They were primarily intended for him to deal with his work projects, but we used them on our own school reports in grade school/Junior High, at a time when practically every other student was writing in longhand or with a typewriter. My first encounter with a "portable" computer was a Compaq Series I like this, complete with a HP Thinkjet thermal printer. Later on, we had an IBM PC XT and PC AT, as well as a Compaq II portable, all on loan from Weyerhaeuser. Dad didn't personally buy our first computer (a Compaq Deskpro 386 Desktop) until sometime around spring 1990. I remember the Compaq portables we had on loan had a fancy travelling case that stored the computer, the printer, had space for software boxes, and paper, and even had a small luggage cart...a far cry from what we have now, with phones far more capable than any of that.
In the Paul College of Business and Economics at UNH they have one of those sitting in a glass case along with other notable business machines. Thanks to you I immediately recognized it! :)
Hey man. No reason to be scared of doing it! So long as you've got money for the hobby and time to learn and tinker, go for it! The only thing I'd be extremely careful with is CRTs. Those beasts are terrifying.
to be fair, its like thinking its the gas ignition not working, not that there is a gas leak, so basically he tried lighting the gas ignition with another gas ignition unaware that the room was full of gas XD
@@Djbiohazard1991 But current is all the same in a closed loop (remember kirkoffs laws?) So fireworks could also come from something that hasn't gone bad
My dad had a version of this that came with an amber monochrome display (I don't think it was a Compaq but the form factor was almost exactly the same). One of the greatest joys was getting old DOS programs like JET and Starflight to work properly, let alone being able to play them. I still fire up a copy of Starflight on a DOS emulator every now and then just for kicks. Formative years and all that. Great video, wish we still had that old machine kicking around but I'm afraid it was long ago consigned to the waste bin. Thanks :)
No need for tools to open the covers. Just lay it flat, and push the plastic cover down in line with the logo. It will pop open on the top by itself. Saving the clips, and no tool damage. BTW, these computers work great off a Hercules Graphics card. Also, this model came with 2 floppy disk drives.The Plus model (with a gold logo) came with a Seagate MFM hard drive installed - 10MB.
Brendan Becker purchased what appears to be this exact same model Compaq and it has been sitting in my studio for well over a year now. So this is super informative. Thanks for sharing!!
This was my dads computer on his Snap-On Tools truck in the late 80s. after he got a new one, he gave that one to my mom, which became my first computer. Lots of memories with this computer.
Its awesome watching someone do something they are passionate about and so well versed in doing. I'll never try to tackle any computer restoration but I'm always glued to every step
My first Windows PC was a Compaq "Lunch box" Portable that a friend of mine found for me at a thrift store for 10 dollars in 1994. Dual 5 and a Quarters and no HD(found one later with a a 10 MB HD later). it brought me into the wonderful world of computing and eventually I learned to rehab and build my own from scratch. It was a world changer for me.
Looks like that capacitor was shorting the rail to ground and the power supply was shutting off to protect itself, it's really common for tantalum capacitors to fail Short Circuit. (Edit: I feel like I should mention to clarify electrolytic capacitors usually fail open circuit or simply loose capacitance, whereas tantalums usually fail Short Circuit.) I find it kind of funny that the modern power supply you plugged in lacked the protection features of the built-in older one. Hope you didn't chuck the original board out as these are fairly rare and it's likely an easy fix.
Yeah, Tantalums had better electrical characterstics than electrolytics, but they fail dead short so often in vintage equipment that most restorers just change them all out wholesale before starting any other testing and repair.
Osaka2407 I don't think most ATX supplies provide all 4 ISA rails (+12V, +5V, -5V and -12V). Old XT era boards didn't use the +3.3V rail common on modern boards. Yet again for this jumpstart, only the floppy rails (+12V and +5V) were used anyway.
Similar thing happened to me on a 286 Octek board. One tantalum blew his head off upon first power up. The failure mode on these is spectacular. The PSU was definitely going into self protect mode when the tantalum shorted out. I was lucky in that I did not have any burnt traces on the board, but the risk is always high. The guy who worked on memtest86 for a long time is designing a smart ATX2AT converter (x86.fr/atx2at-smart-converter/) which can protect mainboards from those kinds of failures by shutting off all power when detecting an unexpected surge in current.
do you have any experience how to debug/fix XT motherboard ? I have one , and after fire up from the speaker I can only hear ( ambulance sound ) , and no POST ;/
I got one of these working from a garage sale around 2001. Had to change some PS caps and had to completely redo the keyboard foams. Everything else worked great. I was in high school. Ended up bringing it to show my computer science class
This brings back memories of the Compaq portable II that I dragged home from the curb one day when I was just a kid... watching this video makes me glad I kept it.
WOW - have you brought back some vague memories for me! I remember first seeing this "portable" in a high-end computer store in San Antonio called Abacus back in... oh hell, probably 1985 or so (they were excited to sell the Apple IIe with dual 5.25" floppies and the the Apple IIc). I loved the Compaq and wanted one so bad even though at that time the base price hovered around $2K or so. What memories... Thanks so very much for taking me back to when PC Jocks did component level testing instead of just replacing a board. Definitely Subscribing!
8-BIT GUY, YOU ARE A TRUE COMPUTER WARRIOR! NEVER GIVE UP (Anders Jensen's music here really fitted the mood, of overcoming adversity/pressing on and being rewarded. Beautiful)
I have a lot of nostalgia for this machine. My dad was a mech engineer and had this. I would beg him to bring it home on weekends so I could play, write code, experiment, etc on it. I'm pretty sure it had a hard disk, so I had my own 5 1/4" floppy i hand crafted that would boot into my section of the hard drive. In the initial stages of creating the separation, I would forget to flip it back to his partition, so a couple of times I had to coach him through rewriting the sectors on the HD... lol. I eventually started playing with modulating the tin-crap speaker in there... only one channel so you could flip between about 2 or 3 different notes real fast and get multi tones. Then I got my hands on a dos program named "player piano", it would take real music files (like play C for 1 unit of time, then D for .25 unit, etc). I was only about 10 years old at the time and I'd be up all night friday night once he got home, then saturday night, then sunday night and try to remember to flip the HD back to his work... LOL Wow. Hope to see it working again. You only truly need 640k of RAM. (snicker) And to be clear, Gates argued the opposite of that. LOL
I love these restoration videos. In today's world were most hardware troubleshooting amounts to replacing the hardware (or the whole computer), it's nice to see hardware actually get fixed and maintained.
Great work in getting as far as you have! Love the music by Anders Enger Jensen. It takes me back to a time in the 80s. Sitting in a dimly lit room at 2am with my Commodore 64 and modem dialling up BBS systems.
Restoration videos are some of the best on the channel, but then again it's really difficult to decide since everything is so well made! Keep up the good work, I know I'll be on the lookout for the rest of the videos in this series!
It's not entirely correct to refer to the Compaq video cards as "CGA", as although they are CGA-compatible, they also offer a high-res 640x350 text mode on the Portable's built-in CRT, giving it much sharper text characters than CGA's 640x200 resolution. Later revisions of the Compaq video card added 640x350 graphics to the built-in CRT, giving it EGA compatibility. p.s. I've heard that early revisions of the Compaq Portable's motherboard have a pinout for a cassette port, although it was never populated or supported.
I enjoy my WUXGA 1920*1200 Hater of the 1920*1080 (shitty for computers) I used to OVERCLOCK my CRT to QXGA 2048 × 1536 from the native 1600* 1200(100hz)
Hey, awhile ago I saw a video of you sorting through old computers that were completely left out, what are those called? I tried looking for computer recycling places but they all don't let people just take stuff.
You are the most interesting "boring nerd" I've ever seen. I LOVE your videos, your straightforward presentation style and your methodical trouble shooting process!
I remember selling those! I was in retail computer programming and sales in the 80's. We sold Eagle, Compaq, IBM, TI, and many others that my poor, surviving brain cell can't bring back. Thanks for the memories!!!
Oh gawd! Not only did I buy one of these for the 2022 equivalent of $9000, I still have it! Last I knew, it still works. On top of the stock build, over time I added an AST 6-Pack Plus card, a Plus-brand HardCard 30, a SoundBlaster audio card, an 8087 math coprocessor, and I'm pretty sure I replaced the CPU with an NEC V20, which performed slightly better than the original CPU. It started with MS-DOS 1.01 and currently has MS-DOS 5.x or 6.X installed. I have the factory carrying case too. "Portable" was a misnomer; I've always referred to the 32-pound computer a "transportable." Buying it was a near-impulse when I was in my mid-20s. I stupidly took out a $2000 personal loan to buy the $3000 computer. Buying it completely redirected my career. Long story short, I spent about 13 years working for Intel! I'd be willing to part with it for the right price.
The Compaq 1 originally had two floppy drives. One of the computer shops biggest profit centers was installing a Seagate 20 meg MFM 5-1/4 form factor hard disk drive into the thing. The power supply was marginal and when ever I did one, I hoped that the power supply would not die quickly under the increased power drain. When the lap top came into use two to three years later, we made money transferring their data from the old Compaq to their new lap top. Brings back many memories of the mid to late eighties in the business.
I remember when these "luggable" PCs first came out; being heralded as a portable PC, with the connotation of Compaq being a "compact" PC. In later years Compaq went to producing decent quality desktop PCs. I have one those boat-anchors in my garage, where its weight and heft does well to anchor, in place, some stiff cabling on the floor in my garage.
this is one of my fav 8BG restorations. its super informative and shows how ridiculously good you are at troubleshooting. thanks for the free entertainment!
And that's *why* it's called a smoketest. XD I once had a Hercules card let magic smoke out of a 486DX5 PC I owned, through the 5.25" floppy drive (!).
Actually, fun fact, "smoke test" was originally a plumbing thing. They'd pump smoke through the pipes to check for any leaks. It crossed over to electronics for obvious reasons.
Dude, I don't even know why I watch your videos. I will probably never rebuild a one of these old beauties, but I can't get enough! Keep 'em coming! Thank you for all the infotainment.
Damn, I had one of these as my first work computer. I worked for a startup consulting company back in the day and it was my BYOD. Brings back memories. I remember when I had to add RAM, swap out a disk drive for a hard drive (and add a controller), replaced the PS(!), and added ISA cards, taking apart the cages was such a pain and I got plenty of skinned knuckles doing it.
Ha, have fun restoring the foam and foil board! To be honest, it's something I've always wanted to try, even though that kind of keyswitch is widely disliked. From memory, I believe it was some sort of model railroading foam that some Apple Lisa restorers found to work best. Something like a sheet of foam used to create the rail bed or something along those lines. Anyways, keep up the great work!
Thank you for this video. It helped me with diagnosing my own issues with this machine. I managed to get a hold of one and it wouldn't boot just like yours. The floppy controller card shot out similair sparks when I plugged it into my 5160 I use to test ISA cards. Once I replaced the blown tantalum the machine booted right up. I'm now waiting for the "foam and foil" pads from texelec so I can complete the restore.
5:53 The magic smoke escaped! Oh, tantalum capacitors, almost always the culprits! Those are the worst! Now that I think about it, I have a netbook that doesn't want to power on. If I discharge the capacitors and plug it, it turns on and back off in just about 2 seconds. Maybe a shorted tantalum capacitor? I suspect the CPU, though, as there were some problems with the (integrated) graphics.
Good video! A couple of suggestions that might help in the future: 1) Those hex-head screws are VERY common on older electronics. Wou need either a NEW flathead screwdriver with very sharp corners on the bit (look at yours at 3:04, you can see how round the tip is) or an accurately fitting hex head, usually 1/4". Since you need to get straight on with the flathead and that isn't always possible, a good 1/4" nut driver is almost always the best way to go. 2) When a power supply gives a quick voltage burst and shuts down, it almost always means one of two things: either there is a short or overload on the output and it has shut down from over-current, or the voltage regulator in the power supply is broken and it has crowbarred for over-voltage. The second is quite rare, and when it does happen is usually a result of a previous short on the output. The right test is to remove all load from the supply and check the output voltage. If it is about right (say within -5% to +15%) the power supply is most likely good and you have a short in the load. If the voltage is very different than what itr should be, the supply may be bad. If you get that flash, immediately check the loads for shorts on the power rails. When I saw that flash from the big supply I was betting that as well as the cap, you had blown traces on the video board, which could have been difficult or impossible to fix since it is probably a multi-layer board with the power on the inside layers. Luckily you blew the trace on the motherboard, where it was easy to fix. Much better to check with the ohm meter first.
Your video is 5 years old now but is invaluable as I work to restore my Compaq Plus. I was able to get it to boot using a Gotek with Flashfloppy (360K or 720K images) but as you found, the keyboard is 100% dead.
Was watching this video when visiting my parents.. then dad peeks over my shoulder: 'Hey.. I got one of those down at the server room at work, want it?' Suddenly i have a Compaq Portable that I have to clean up.
Sell it, or give it away to this guy.
I worked with plenty of this junk as a kid, it is perplexing to me why anybody want to collect it, but I am an engineer - we build better stuff today.
I think you're going to be disappointed. It belongs on a museum, and I don't think it's useful for anything when you can simulate it at the gate level today - and you probably won't even do that ever.
@@fuzzywzhe Why do people collect anything at all? Why do we have emotional attachment to inanimate objects? Doesn't matter if we can emulate it to the molecular level.
How funny. Someone gave me one of these, too. And it's in the same state as David's. Fan comes on, but no display and no activity. I suspect a bad power supply.
@@leandrotami I didn't mean to sound critical, I just don't understand why people collect this stuff.
If I want to relive an experience from my childhood with a computer, it's the experience of using the machine, and simulation is 100% accurate with the machines I used.
I would never own a C=64 again simply because compared to the machine I have today, it's a waste of electricity to even turn it on. My VASTLY more powerful computer can simulate 20 of them running at the same time on 1 machine, and use less power.
But it's fine if you use actual hardware, of course. I just don't understand it.
My Grandpop has one in his attic, he will let me have it if I past all my classes this year.
From an age where "portable" means "it has a handle on the case."
That ended with the gamecube
Gameboy anyone?
Tahngarthorl
@@russellhumphrey7154 wut?
@@miinaemad749 mememememememe
"So i accidentally blew out a Capacitor but the surprising thing is it powers on now"
*The Engineer*
endjiner
"Hey look buddy, im an engineer. That means i solve problems."
@@TFD_Animations "Not problems like 'What is beauty?' Because that would fall within the purview of your conundrums of philosophy."
@@stuntboy0372“I solve practical problems”
Truss me, I’m an engineer
I'm so glad there are people like you out there keeping this old stuff alive. I feel like you are doing a valuable service for the world by keeping this stuff in living memory.
I'm waiting for him to demonstrate an Babbage Machine or an Astrolabe.
How about an internal combustion engine? He's just demonstrating what he grew up with, he has no understanding what that's been based upon. Have him demonstrate a radio built entirely with tubes, explaining how the tubes work. They are similar to transistors, but I bet he has no idea how they function.
5:55 "that was a bit unexpected" --that's totally what I expected 😂
One way to find a dead short lol power through it hahah
Yeah... this was totally what I expected too...
LOL me too. I was like, "No no no. Bad idea!" : -)
I thought about starting a thread about this but didn't want to come off as a know it all so I'll just post it here. Yeah, I was expecting that too. As soon as I saw the blinking LED I thought "yep, shorted capacitor somewhere." At least blowing it up allows one to find the bad one, LOL.
the blue djinn has been released
5:38 "Nobody could think of a good reason not to"
5:53 *capacitor blows up*
This comment aged like fine wine
Meh a little bit of fire never hurt anyone
Who thinks these restorations are fun to watch
5:53
It totally worked
Computer: "Current date is Tue 01/01/1980
Oh, honey...
and ronald reagan is president
1980-01-01 was during the Carter administration.
RaineMan213 HAPPY OLD YEAR!!!
Richard Benson bedtime for bonzo
Somer Erickson still is but they call it Socialism now.
As someone who enjoys the restoration process, but is not much of historian or expert of the computers of old, I'm very impressed with the design, with the modular parts, and the rubber mounts!
You might have luck getting that handle fixed at a local shoe repair place. They can work wonders on just about any type of leather application.
Just hope what ever he decides, he doesn't send it off to some commenter saying they'll fix it for free and never be heard from again.
it is hardly rocket surgery to redo the stitches with needle and thread
great idea!
Seannyyx I still kind of wonder what that guy's deal was, was he just a wierdo who really wanted an old leather handle for some reason, or was he a legit amateur leatherworker who bit off more than he could chew and ghosted David because he messed the handle up?
Whoever he was he should swallow his pride and just send it back, even if he fucked it up.
Wow that power supply jump-start is some MacGyver-level s#!t!
"Broken Compaq? I'll need four paperclips and some chewing gum" 😂
Brilliant lol
And includes some stuff blown up.
Have you not used two power supplies ever?
I had to jump start my graphics card because my current power supply didn't have enough energy to supply.
I've done something similar before, so it was nice to see.
Got an 1100W powersupply in my pc. Works nice. Little overrated maybe...
5:38 "oh sure yeah don't worry everything will be fine" yeah famous last words, huh? :P at least it all worked out in the end. looking forward to part 2, these repair videos are always fun to watch!
I have one of these! Bought it for $25 at a garage sale in '06. Perfectly working with a 20mb HDD(full of old psych patient records) and a full set of software & even a printer too. The software & printer were sadly lost over multiple moves in the last 14 years but I still have the Portable in storage. Amazing system and I actually used it for a while for writing.
"So I went down to my friends house who had this random, defunct, wort hless1980's electronic board laying around for years that was just the thing I needed" You have some awesome, but odd friends.
Everyone wishes they had friends like these.
I am that friend.
@TheLegendkiller2100 Yup. I collect old, esoteric, outdated junk.
djdrew11 and I collect junk in general
@@DalekCraft me too lol.. trouble is I now need a bigger display case. I seem to have filled this one up, barely room for myself, daughter and the three cats. :D Only joking, always room for more useless rubbish I hang onto incase I may need it lol.. I swear I have a draw FULL of old phone chargers, pc cables going back YEARS, and printer cables and related parafunalia.. ink etc lol.
I love these restoration videos never stop doing them!
Edit: wow didn’t expect to 100 likes thanks guys!
Thanks for what? Do people think this makes them famous or something?
RUclips User sorry if I offended you. It’s just the first time I’ve gotten more than 20 likes
@@rrrailroad6888 you didn't offend him. It's just annoying as hell. Like what are you, 12?
Looking forward to the Part 2! I actually went through about this same adventure with my Compaq Portable. It turns out that the power supply is smart and if too much current is drawn, it will shut down to prevent damage. Those darn tantalum's are a huge problem in electronics this age. I ended up having one of them on the motherboard and one on the video card that were shorted. Found them by pulling the motherboard and testing the power rails using a bench power supply. Turn it on briefly and use a thermal camera to look for hot spots which show up pretty fast. Pull and replace the cap and fixed! I think my floppy controller had a bad can oscillator on it too which seemed like an odd failure, but was also easily to replace. The AC filter smoked not long after playing with it and was to be expected according to many who were giving me advice. This got it booting, both floppy drives worked great right off the bad. Keyboard problems were the next thing I found with the bad foams - replaced those. The last problem was that some video characters would inadvertently change on occasion. Used a Hakko FR300 to remove DRAM's from the memory board and replaced them and solved that. These things can be quite a bit of work to get working, but they are really cool machines. I think you can use a ctrl-alt combination to switch between a true mono mode and cga mode. Maybe ctrl-alt-< and ctrl-alt-> or something like that.
LED: *Doesn’t stay on*
8-Bit Guy: *Jumpstarts with external power supply and blows capacitor*
Same LED: *Now fully functional*
Me: Barbaric problems call for barbaric solutions
He used a barbarian knock spell on it
Im A Mango nobody fucking cares reddit degenerate
ツJEVILOGEN “degenerate” says the guy with the “ツ” smiley in their name.
Dont get it
Gotta agree with Jevilogen
The 80's Montage music during the disk drive teardown was the most exciting few minutes ever on this channel.
I couldn't agree more. Found the music here: soundcloud.com/eox-studios/tlg-carmens-theme
Jeremy Mitchell and not when the capacitor exploded lol?
Brings back so many memories. Staying up all night downloading games and apps from local BBS sites at 2400 baud, around 220 bytes per second with the zmodem protocol if I remember correctly. Great machine.
You had a 2400 baud modem? PSHAW! My first modem was a 300 baud manually switched Radio Shack model. It was a couple of years before I traded up to a genuine Hayes 2400 baud unit.
Rick C. Hodgin I hope you remembered to turn on crash recovery
Very enjoyable video, as always. I don't really understand anything about programming or electronics, and I was growing up around more contemporary devices, but I still like to watch you work on these machines, and learn a bit.
However the 8 bit guy never expected a Capacitor to explode but bad Capacitors that are faulty CAN explode
"Nevertheless, i was able to coax it into loading Planet X3"
Adds are getting smarter nowadays.
A plug to be sure, but a welcome one.
Yep
Time stamp
I had one of these when I was a young teen. It was hopelessly obsolete when I got it, but it had one advantage, my parents didn't know that it functioned and the modem worked.
In a nutshell, I would use it to dial to BBSes at night when I was grounded from the family computer. Nothing like an 8" greenscale screen and a 2400 baud modem. Ran MS-DOS 3.3.
Mine didn't have a hard disk, just dual 5.25" floppy drives.
TWX1138 alright, let a ‘younggen in on it- what’s a BBS?
Yeah, BBS - Bulletin Board system is very much like a web page but run by one person or company and you connect to it by dialling a specific phone number.
I used some around 1993 and 1994 (downloaded shareware games from them mostly), right when the internet was starting, but the internet very quickly made them obsolete.
Though... You could still find a decent number of them up into 1998 or so...
And even to this day there are still a few random holdouts.
The thing about a BBS is that anyone with a computer, a few modems and a few phone lines could technically set one up.
Nowadays I suppose even phone lines themselves are becoming borderline obsolete technology though.
So I suspect BBS will die a final death whenever fixed line phones do.
There's still quite a few BBS'es out there, but nowadays most are set up to be connected to via telnet. No more waiting an hour for a single jpeg to download via X/Y/ZModem!
@Samar Nadra: 14400? How luxurious. Try 2400 baud.
The city library system's BBS also had a Usenet portal, so I was able to do newsgroups, albeit quite slowly. Had to be judicious as to what conversation threads I viewed.
@Kuralthys: yep. Bulletin Board Systems. Basically good for forums, e-mail (including cross-BBS e-mail with Fidonet and one's offlline mail reader like Bluewave), and some limited file transfer and shareware distribution. Some BBSes had multiple phone lines and allowed for teleconferencing, but because of the popularity of that feature those BBSes were either congested or cost money to use.
15:20 When you hear that synthwave music kicking in, you know things are getting SERIOUS!
Has he said where he gets his music from? I know he had a CD with some of his compositions on it. Is this a track of that CD?
the video lists the music used at the end.
Smooth Bed 2
Mr.Drum & Bass 1
The Last Goddess - Carmen's Theme
One or more of those are from someone named Anders Enger Jensen.
And none of them seem to be part of the music collections offerd on 8-bit guy's site.
Ok, a quick search pulled up Jensen's RUclips channel on the last song:
ruclips.net/video/X-ZMgflCu98/видео.html
Sounds like what 8bit was using for the drive disassembly.
That instantly brought me to Tron, the arcade power up clip.
What is the song
@@SirFrag32 Tron, now that's a good film!
Glad to see one of these again. I hauled one of these "portable" machines with me when traveling on business to Mexico in the early 1990’s. "Loved" taking it through airports and on to planes.
I really love how you work your way through each problem methodically to get one step closer to booting. Really great stuff
This was quite the emotional rollercoaster
LOL! True!
I ran into this exact same problem with tantalum caps on the ISA riser of an old 286. A VOM is a better diagnostic tool than pyrotechnics.
but not as fun or cool looking XD
A "VOM" ?
Miles Prower A "Volt-Ohm Meter." Basically, a "VOM" is a multimeter.
Okay ^.^'
A VTVM if you’re really old, or a Simpson 260
> 15:53
"So the first thing I did was to re-lubricate everything and then I started working the head back and forth..."
I lol'd.
Who knew computer restoration could get so...sensual ;)
( ͡° ͜ʖ ͡°)
Wow can’t believe I didn’t see that lol
"... and I actually hear some activity."
@@FernieCanto hm
I don't have much interest in retro-computing nor the resources to store old stuff but your videos are great troubleshooting training material. Learned a lot about how to troubleshoot from watching you. Thank you such much 8-Bit Guy.
5:53 I didn't realise I was watching ElectroBOOM.
Lol that's a good channel to.
Colby Pacholko nah it’s good but very dangerousn
Cio Dokop yeah but he knows most of the time what he is doing.
Colby Pacholko Unlike eclectic boom
I know I will do something stupid but nah who cares let me touch.....
Me: JUMPS OF THE CHAIR
ME: Fucking hell
Electro boom: FUCKING HELL
Viktor Rucký They should make a video together. It would be awesome
Great video! I have never used an old Compaq. But I love seeing your diagnostic process / walkthrough and all your troubleshooting, trial and error. While others may breeze through such things with montages, I appreciate that you documented every step of the way.
Geez, I’m feeling old right now. I was there when these were the best thing!
I used to service these and many other computers of similar vintage. Olivetti, Compaq, Alpha Micro, IBM. Back in the day when businesses used to call service companies to fix things. Reseating chips, cleaning out the dust, cleaning edge connectors, disassembling keyboards cleaning and fixing them.
Chasing logic circuits to find the one chip that was dead was a passion and very rewarding!
Wow, does that bring back memories. Through my late father, my sister and I gained exposure to a variety of computers in the late 70s/early-mid 80s, more so than many of our peers. Dad was a Financial Manager in Forestry R&D for Weyerhaesuer, and not only did we get to interact with the DEC VAX mainframes in the basement with the communal Courier terminals just a few yards from his office, but he regularly brought home computers on extended loan. They were primarily intended for him to deal with his work projects, but we used them on our own school reports in grade school/Junior High, at a time when practically every other student was writing in longhand or with a typewriter. My first encounter with a "portable" computer was a Compaq Series I like this, complete with a HP Thinkjet thermal printer. Later on, we had an IBM PC XT and PC AT, as well as a Compaq II portable, all on loan from Weyerhaeuser. Dad didn't personally buy our first computer (a Compaq Deskpro 386 Desktop) until sometime around spring 1990. I remember the Compaq portables we had on loan had a fancy travelling case that stored the computer, the printer, had space for software boxes, and paper, and even had a small luggage cart...a far cry from what we have now, with phones far more capable than any of that.
Every time I hear music in your videos it takes me back to 1989 and I'm a kid again. Thank you and thanks to Anders.
I'm a simple man, I see a restoration video, I click.
We are two of the same.
In the Paul College of Business and Economics at UNH they have one of those sitting in a glass case along with other notable business machines. Thanks to you I immediately recognized it! :)
5:47 " yeah, I think that will work". The last sentence spoken by many deceased inventors and hobbyist throughout history.
Always great to see you fix old computer systems. I am a little jealous and wish I was as smart and brave to try doing those sort of fix/restorations.
Hey man. No reason to be scared of doing it! So long as you've got money for the hobby and time to learn and tinker, go for it! The only thing I'd be extremely careful with is CRTs. Those beasts are terrifying.
Shall we get the multi-meter and search for the short?
*Grabs 500w PSU*
Nah
That's like looking for gas leaks with a lighter xD
to be fair, its like thinking its the gas ignition not working, not that there is a gas leak, so basically he tried lighting the gas ignition with another gas ignition unaware that the room was full of gas XD
That was a very Slav thing to do, maybe needs an ancestry test to determine how much slavness runs in his blood
Basically my last ditch effort debugging equipment. Short the fuse with a nail, and see where the fireworks come from.
@@Djbiohazard1991 But current is all the same in a closed loop (remember kirkoffs laws?) So fireworks could also come from something that hasn't gone bad
My dad had a version of this that came with an amber monochrome display (I don't think it was a Compaq but the form factor was almost exactly the same). One of the greatest joys was getting old DOS programs like JET and Starflight to work properly, let alone being able to play them. I still fire up a copy of Starflight on a DOS emulator every now and then just for kicks. Formative years and all that. Great video, wish we still had that old machine kicking around but I'm afraid it was long ago consigned to the waste bin. Thanks :)
This may have been one the most challenging restorations but it makes for great watching. Really varied and involved. Love it.
Wow. That's some dedication to getting it fixed!
No need for tools to open the covers. Just lay it flat, and push the plastic cover down in line with the logo. It will pop open on the top by itself. Saving the clips, and no tool damage. BTW, these computers work great off a Hercules Graphics card. Also, this model came with 2 floppy disk drives.The Plus model (with a gold logo) came with a Seagate MFM hard drive installed - 10MB.
The plus model sounds really cool honestly
Brendan Becker purchased what appears to be this exact same model Compaq and it has been sitting in my studio for well over a year now. So this is super informative. Thanks for sharing!!
This was my dads computer on his Snap-On Tools truck in the late 80s. after he got a new one, he gave that one to my mom, which became my first computer. Lots of memories with this computer.
Send the Handle to the same guy that did the Osbourn Handle LOL
After the Osborne debacle, I'm guessing that guy has gone into hiding.
Or tanning.
Hahahahahahahahahaha!!!
No.
Kelvin Broder yeah I’d have to agree
Lmao yes!
MISSED YOU SO MUCH
Its awesome watching someone do something they are passionate about and so well versed in doing. I'll never try to tackle any computer restoration but I'm always glued to every step
My first Windows PC was a Compaq "Lunch box" Portable that a friend of mine found for me at a thrift store for 10 dollars in 1994. Dual 5 and a Quarters and no HD(found one later with a a 10 MB HD later). it brought me into the wonderful world of computing and eventually I learned to rehab and build my own from scratch. It was a world changer for me.
Looks like that capacitor was shorting the rail to ground and the power supply was shutting off to protect itself, it's really common for tantalum capacitors to fail Short Circuit. (Edit: I feel like I should mention to clarify electrolytic capacitors usually fail open circuit or simply loose capacitance, whereas tantalums usually fail Short Circuit.) I find it kind of funny that the modern power supply you plugged in lacked the protection features of the built-in older one.
Hope you didn't chuck the original board out as these are fairly rare and it's likely an easy fix.
David Scheiber maybe that jump-start he did somehow didn't trigger the PSU over current protection
Yeah, Tantalums had better electrical characterstics than electrolytics, but they fail dead short so often in vintage equipment that most restorers just change them all out wholesale before starting any other testing and repair.
Osaka2407 I don't think most ATX supplies provide all 4 ISA rails (+12V, +5V, -5V and -12V). Old XT era boards didn't use the +3.3V rail common on modern boards. Yet again for this jumpstart, only the floppy rails (+12V and +5V) were used anyway.
Similar thing happened to me on a 286 Octek board. One tantalum blew his head off upon first power up. The failure mode on these is spectacular. The PSU was definitely going into self protect mode when the tantalum shorted out. I was lucky in that I did not have any burnt traces on the board, but the risk is always high. The guy who worked on memtest86 for a long time is designing a smart ATX2AT converter (x86.fr/atx2at-smart-converter/) which can protect mainboards from those kinds of failures by shutting off all power when detecting an unexpected surge in current.
do you have any experience how to debug/fix XT motherboard ? I have one , and after fire up from the speaker I can only hear ( ambulance sound ) , and no POST ;/
I honestly love watching these restoration videos. Reviving old tech is an awesome skill to have! Cheers! 👍🏻
I love that genuine fear when capacitor blew up. Btw, I'm huge fan of the channel.
I got one of these working from a garage sale around 2001. Had to change some PS caps and had to completely redo the keyboard foams. Everything else worked great. I was in high school. Ended up bringing it to show my computer science class
15:24 Love it when the 80s synth montage music kicks in
Always love seeing the patreon notification from a new video of yours David! Appreciate the consistently brilliant content 😀
ikr
This brings back memories of the Compaq portable II that I dragged home from the curb one day when I was just a kid... watching this video makes me glad I kept it.
WOW - have you brought back some vague memories for me! I remember first seeing this "portable" in a high-end computer store in San Antonio called Abacus back in... oh hell, probably 1985 or so (they were excited to sell the Apple IIe with dual 5.25" floppies and the the Apple IIc). I loved the Compaq and wanted one so bad even though at that time the base price hovered around $2K or so. What memories...
Thanks so very much for taking me back to when PC Jocks did component level testing instead of just replacing a board. Definitely Subscribing!
This video notification made my day better.
8-BIT GUY, YOU ARE A TRUE COMPUTER WARRIOR! NEVER GIVE UP
(Anders Jensen's music here really fitted the mood, of overcoming adversity/pressing on and being rewarded. Beautiful)
I have a lot of nostalgia for this machine. My dad was a mech engineer and had this. I would beg him to bring it home on weekends so I could play, write code, experiment, etc on it. I'm pretty sure it had a hard disk, so I had my own 5 1/4" floppy i hand crafted that would boot into my section of the hard drive.
In the initial stages of creating the separation, I would forget to flip it back to his partition, so a couple of times I had to coach him through rewriting the sectors on the HD... lol.
I eventually started playing with modulating the tin-crap speaker in there... only one channel so you could flip between about 2 or 3 different notes real fast and get multi tones. Then I got my hands on a dos program named "player piano", it would take real music files (like play C for 1 unit of time, then D for .25 unit, etc).
I was only about 10 years old at the time and I'd be up all night friday night once he got home, then saturday night, then sunday night and try to remember to flip the HD back to his work... LOL
Wow. Hope to see it working again. You only truly need 640k of RAM. (snicker) And to be clear, Gates argued the opposite of that. LOL
Love what you do man! Preserving history, dont stop!
That pop, fire and smoke scared the crap out of me. I like the music.
I loved the '80s montage music during the disk and keyboard work (and the end). Lane Meyer would approve!
I love these restoration videos. In today's world were most hardware troubleshooting amounts to replacing the hardware (or the whole computer), it's nice to see hardware actually get fixed and maintained.
You mean we're(short for we are)
Post-cards...real blast from the past. We had one in the first workshop I worked in.
Thank goodness that they need restoration. These are by far my favorite videos of yours. Good luck with them!
5:55 For a moment I thought I'm watching ElectroBOOM instead of The 8-Bit Guy
Great work in getting as far as you have!
Love the music by Anders Enger Jensen. It takes me back to a time in the 80s. Sitting in a dimly lit room at 2am with my Commodore 64 and modem dialling up BBS systems.
Restoration videos are some of the best on the channel, but then again it's really difficult to decide since everything is so well made!
Keep up the good work, I know I'll be on the lookout for the rest of the videos in this series!
Congrats on 750K!
It's not entirely correct to refer to the Compaq video cards as "CGA", as although they are CGA-compatible, they also offer a high-res 640x350 text mode on the Portable's built-in CRT, giving it much sharper text characters than CGA's 640x200 resolution. Later revisions of the Compaq video card added 640x350 graphics to the built-in CRT, giving it EGA compatibility.
p.s. I've heard that early revisions of the Compaq Portable's motherboard have a pinout for a cassette port, although it was never populated or supported.
I enjoy my WUXGA 1920*1200 Hater of the 1920*1080 (shitty for computers)
I used to OVERCLOCK my CRT to QXGA 2048 × 1536 from the native 1600* 1200(100hz)
VWestlife fancy seeing you here
Hey, awhile ago I saw a video of you sorting through old computers that were completely left out, what are those called? I tried looking for computer recycling places but they all don't let people just take stuff.
It's an "e-waste" dropoff point.
I have a Ford Galaxie 500.
You are the most interesting "boring nerd" I've ever seen. I LOVE your videos, your straightforward presentation style and your methodical trouble shooting process!
I remember selling those! I was in retail computer programming and sales in the 80's. We sold Eagle, Compaq, IBM, TI, and many others that my poor, surviving brain cell can't bring back. Thanks for the memories!!!
The 8bit Necromancer!
2:02 "Let's see what it does!"
*Explosion*
"Well, now I know what the guy was talking about; it clearly doesn't work!"
6:12
I love how that one specific capacitor, the power supply was like "nope, not having any of that"
These restoration vids are the bread and butter of this channel and are very comfy. Great editing on these as usual.
I was jokingly thinking to myself, "this thing is gonna explode when you add an external power supply", and then it exploded. 0_x
Well at least it was ONLY the Capacitor that exploded
Cap had shorted and you blew out the short.
Oh gawd! Not only did I buy one of these for the 2022 equivalent of $9000, I still have it! Last I knew, it still works.
On top of the stock build, over time I added an AST 6-Pack Plus card, a Plus-brand HardCard 30, a SoundBlaster audio card, an 8087 math coprocessor, and I'm pretty sure I replaced the CPU with an NEC V20, which performed slightly better than the original CPU. It started with MS-DOS 1.01 and currently has MS-DOS 5.x or 6.X installed. I have the factory carrying case too.
"Portable" was a misnomer; I've always referred to the 32-pound computer a "transportable."
Buying it was a near-impulse when I was in my mid-20s. I stupidly took out a $2000 personal loan to buy the $3000 computer. Buying it completely redirected my career. Long story short, I spent about 13 years working for Intel!
I'd be willing to part with it for the right price.
The Compaq 1 originally had two floppy drives. One of the computer shops biggest profit centers was installing a Seagate 20 meg MFM 5-1/4 form factor hard disk drive into the thing. The power supply was marginal and when ever I did one, I hoped that the power supply would not die quickly under the increased power drain. When the lap top came into use two to three years later, we made money transferring their data from the old Compaq to their new lap top. Brings back many memories of the mid to late eighties in the business.
This was great fun to watch. I wish there were two of you so I could get uploads twice as often.
I remember when these "luggable" PCs first came out; being heralded as a portable PC, with the connotation of Compaq being a "compact" PC. In later years Compaq went to producing decent quality desktop PCs.
I have one those boat-anchors in my garage, where its weight and heft does well to anchor, in place, some stiff cabling on the floor in my garage.
You can't call a device a portable device when it looks like it weighs a ton
It's amazing how long Molex connectors have been around. Literally 40 years, still the same connectors on modern PSUs.
why does this computer not come with an core i7-12900k bro
this is one of my fav 8BG restorations. its super informative and shows how ridiculously good you are at troubleshooting. thanks for the free entertainment!
5:51 As uxwbill would say, SMOKE TESSSSSSSSST!
And that's *why* it's called a smoketest. XD I once had a Hercules card let magic smoke out of a 486DX5 PC I owned, through the 5.25" floppy drive (!).
I sorted a power supply on a 486 once. Remember when you had to orient the power switches on home built computers?
Think I toasted a PS on a 386 the same way.
Actually, fun fact, "smoke test" was originally a plumbing thing. They'd pump smoke through the pipes to check for any leaks. It crossed over to electronics for obvious reasons.
Or AvE, it let the smoke out along with the angry pixies.
5:53 When The 8-Bit Guy turned into ElectroBOOM
Dude, I don't even know why I watch your videos. I will probably never rebuild a one of these old beauties, but I can't get enough! Keep 'em coming! Thank you for all the infotainment.
Damn, I had one of these as my first work computer. I worked for a startup consulting company back in the day and it was my BYOD. Brings back memories. I remember when I had to add RAM, swap out a disk drive for a hard drive (and add a controller), replaced the PS(!), and added ISA cards, taking apart the cages was such a pain and I got plenty of skinned knuckles doing it.
Ha, have fun restoring the foam and foil board! To be honest, it's something I've always wanted to try, even though that kind of keyswitch is widely disliked. From memory, I believe it was some sort of model railroading foam that some Apple Lisa restorers found to work best. Something like a sheet of foam used to create the rail bed or something along those lines. Anyways, keep up the great work!
Search ebay for "victor foam pads". Try to reuse the foil if possible.
Model Railroading foam would probably be Woodland Scenic's "Track Bed" product. Not sure what scale though. Probably HO. #modelrailroader.
These folks sell pre-made replacement pads:
texelec.com/product/foam-capacitive-pads-keytronic/
Awesome episode. I love these old luggables.
Thank you for this video. It helped me with diagnosing my own issues with this machine. I managed to get a hold of one and it wouldn't boot just like yours. The floppy controller card shot out similair sparks when I plugged it into my 5160 I use to test ISA cards. Once I replaced the blown tantalum the machine booted right up. I'm now waiting for the "foam and foil" pads from texelec so I can complete the restore.
I found your channel 1 year ago and I couldn’t stop watching I took computer science in 3 grade cause of you. keep up the great work
5:53 The magic smoke escaped! Oh, tantalum capacitors, almost always the culprits! Those are the worst! Now that I think about it, I have a netbook that doesn't want to power on. If I discharge the capacitors and plug it, it turns on and back off in just about 2 seconds. Maybe a shorted tantalum capacitor? I suspect the CPU, though, as there were some problems with the (integrated) graphics.
5:52
I haven't seen this yet but I don't think its going to end well
Edit: I was right
I love watching these restoration videos. It helps me want to go show love to these older machines and make them work again.
Good video!
A couple of suggestions that might help in the future:
1) Those hex-head screws are VERY common on older electronics. Wou need either a NEW flathead screwdriver with very sharp corners on the bit (look at yours at 3:04, you can see how round the tip is) or an accurately fitting hex head, usually 1/4". Since you need to get straight on with the flathead and that isn't always possible, a good 1/4" nut driver is almost always the best way to go.
2) When a power supply gives a quick voltage burst and shuts down, it almost always means one of two things: either there is a short or overload on the output and it has shut down from over-current, or the voltage regulator in the power supply is broken and it has crowbarred for over-voltage. The second is quite rare, and when it does happen is usually a result of a previous short on the output. The right test is to remove all load from the supply and check the output voltage. If it is about right (say within -5% to +15%) the power supply is most likely good and you have a short in the load. If the voltage is very different than what itr should be, the supply may be bad. If you get that flash, immediately check the loads for shorts on the power rails.
When I saw that flash from the big supply I was betting that as well as the cap, you had blown traces on the video board, which could have been difficult or impossible to fix since it is probably a multi-layer board with the power on the inside layers. Luckily you blew the trace on the motherboard, where it was easy to fix. Much better to check with the ohm meter first.
7:22 “But there’s still 3 wildcards.”
Don’t you mean *3 CGA cards?*
5:55 "That was a bit unexpected"
YA THINK!?
Man, I just love seeing broken old computers slowly come back to life.
Your video is 5 years old now but is invaluable as I work to restore my Compaq Plus. I was able to get it to boot using a Gotek with Flashfloppy (360K or 720K images) but as you found, the keyboard is 100% dead.