IBM 5150 resurrection. Failed PSU and shorted expansion cards
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- Опубліковано 7 сер 2024
- Join me in my attempts to save my IBM 5150.
After a spectacular PSU failure and a shorted expansion card, I'm trying to get the system up and running again.
Follow me as I make mistakes, get certain insights and throw in some lessons learned at the end
Also, lots of thanks to the visitors / maintainers of the following sites :
RetroMachines facebook group : / retromachines
Vintage Computer Federation Forums:
www.vcfed.org/forum
Great reference for all IBM 51xx PC Family Computers:
minuszerodegrees.net - Наука та технологія
Actually the most beautiful capture of Magic Smoke I've seen. This is something for the EEVBLOG.
We aim to please .... :)
These step-by-step repair videos are incredibly useful and valuable. They are the kind of thing that you can’t learn from a book or manual because you need to be shown what to test, how to test it, how to remove it, etc. Thank you!
Very helpful video. Thank you! My 5150 PC is arriving this week and it hasn't been turned on for at least 20 years, so I'm considering what to do when it arrives.
Power supply.
See blown RIFA cap.
Every electrical engineer: "Friggin RIFA's"
The power supply will probably work again if you replace that blown RIFA with a standard class X2, 2kv capacitor.
Also check the working power supply to see if it also has a RIFA capacitor in it and replace it if it does or the smae thing will happen.
I have a power supply for a 5162 in my 5150; it was new-old-stock and came from a local electronics shop which closed a few years back. I bought it specifically so I could safely use a Seagate ST-4096 hard disk in it. The RAM expansion board I am using is a rather rare one from Sweet Electronics which I found upon chance on eBay for $24.
Nice... a lot of diskspace for an IBM pc :) beats working with floppies. And always nice to have working hard drives in there. I like the convenience of xt ide related stuff, but nothing beats the sound of a good working mfm drive :)
Your video here, has given me some ideas on a how to repair an Amstrad IBM XT Clone (PC 3086). Was reading a short that might not be a short at all. Will have to get test the resistance again the next time I have some free time. I've been working on this computer for a very long time & I'm committed to getting it up and running again.
Love seeing good, classic hardware up and running again.
"Magic smoke"... The computer was having a ganja...😅
IIRC, the 12V on the CGA card is only a pass-through to the light-pen and RF-modulator connectors.
very nice video.....not sure what happened between then and now but this style of video is really good..... IMO
Remaining tantalum capacitors will fail short sooner or later. If one have failed it is better to replace them all, instead of waiting for next to fail. At some point one may fail in a fatal way, e.g. burning the tracks on the PCB.
exellent review!
""Azerty"" layout, french DOS ...
J'ai bien aimé cette vidéo :)
Let's continue in english.
It reminds me of my XT clone : the cards were fine (except the IO card that had a leaky battery for the RTC that totally destroyed it), but it didn't want to turn on at all. The HDD had 3 tantalum caps that had failed and this was preventing the PSU from turning on ...
Then I discovered the PSU was being a bit flaky because the computer crashed randomly, which didn't happen with other PSUs, after a recap it was fine again.
I did some footage of it on my channel (They're in french, but I bet you don't have problems understanding french ^^). It's not high-quality at all (and my phone's camera sucked at the time), but at least you can see the progress ...
Nice un français !
Sometime, you should invest in a variac. You can plug something into it and slowly use the dial on the variac to bring it to line voltage slowly. This is useful for old electronics to help keep old components from exploding due to the sudden voltage.
I hope i can get 5150 one day.
The prices are crazy
Good job, i love it :)
I see old PC collectors replace the tantalum caps with electrolytic, because they're supposedly more reliable. Classic Mac owners replace leaky electrolytics with tantalums, because tantalums fail completely at once, obviously. Electrolytics can leak for a long time, ruining everything around them, undetected. Maybe we need an entirely different kind of capacitor altogether!
The best option is replace power supply circuit with a new board like atx sfx.
Hey RetroSpector
I just received my IBM 5150 back for the Jacksonville Museum, and for some reason, it is no longer working. When I power it up, the fan inside the PS,
seems to spin, but a little bit slower then I would think that it should spin.
I am not getting anything out on the 5V or 12V line, with all cards and the MB connected or disconnected.
With all boards and one Floppy with power cord connected I get 81.9ohms and 26.8ohms with FDC installed
On the 12V side I am getting 593ohms with all cards installed. This seems like it might be a little high.
Reach out and touch faith!
It looks not like MS-DOS, but like IBM PC-DOS.
That wasn't necessarily unavoidable. Antique radio collectors have long used a variac to slowly power up radios which haven't been powered in decades. This sometimes can reform the aluminum oxide layer in old capacitors so that they do not blow.
Of course in more complex modern switching supplies some of the capacitors might not even see power until the voltage is high enough to blow them. To save those you would have to remove them from the circuit, power them up slowly with a variable dc supply then put them back.
The capacitor that blew for you though I believe comes right after the power switch with no active components isolating it so the variac trick might have worked.
i used variac on crt tvs
mains filter cap, thats a refa brand, those go bad, its what they do.
I have an IBM 5150 with a dead PSU. Can I use an AT power supply from the 90's to power the original IBM motherboard?
am working to restore a 5150, i have a doubt, the talantio cap.....the positive is the center pin?? is right?
You can find a lot of information on tantalum capacitor polarity here : en.wikiversity.org/wiki/Tantalum_capacitors#Polarity and here for the three legged ones : minuszerodegrees.net/failure/failure%20-%203lt.htm
Most likely. You can remove the capacitor and measure the resistance between the empty pads and ground. If the a solder pad had low resistance to ground, that would be the negative. To be honest those are power supply bypass capacitors. It's ok to simply remove the bad one and power it up without it just for testing.
Hi, it seems your 5151 monitor isn't working properly, the image looks squashed. I'm no CRT expert but it seems that the CRT gun is not opening vertically properly.
The vertical height can be adjusted but you need to open up the monitor and I haven't gotten around to it yet (even now almost a year after this video I am ashamed to say). But in my defense, I have another 5151 that is properly aligned and uses the full height of the screen. Hope you enjoyed the video !
@@RetroSpector78 I did, i discovered your channel recently, and i like your laid back relaxed style. Keep up the good work!
@@YarisTex Thx a lot for the feedback ... glad you are enjoying it ... feel free to help and spread the word ... subscribers and watch time are a big deal on youtube, and both are difficult to get for new channels....
I need some manuals and info so I can trace a lot of errors in my pc-xt motherboard. Any help would be much appreciated.
Did you find any?
@@GamePlayShare sadly no. but i have found some guys that docummented on videos.
@@GamePlayShare so far apparently the motherboard is fine but has no processor or ram installed
Why does a CGA card need 12 volts?
I had a look through the schematic, but the only place it looks like the 12V rail goes is to the "feature connector". Didn't seem to be used by anything else on the board itself.
Edit: actually that was the EGA adapter, but the CGA adapter schematic still only shows 12V going to some headers and not being used on the board itself.
I whod just shuve a modern one less risk off fire
PLEASE use anti-static measures when working on vintage computers.
Static discharge really will damage CMOS parts and especially RAM in intermittent and infuriating ways.
Great advice and indeed something that is often overlooked. Will try to make use of my anti-static wristband in future videos. Hope you enjoyed the video.
this might be seen as a mean comment, but you totally need to stop breathing through your mouth and breathing into the mic and clicking your tongue against the back of your throat. it's extremely audible and really disconcerting when listening to this video. i hope this is something you can improve - your content is great, but i know a lot of people will find it difficult to listen to this video.
Will try to work on that ...
@@RetroSpector78 thank you - i really appreciate the work you're putting into this! it's not easy so it'll take a lot of practice. there are tutorials out there on how to record spoken word. some starting points: turn your face when breathing out, close your mouth at all times, breathe through your nose, speak with your diaphragm.
Thanks for producing your informative and entertaining videos. Your pronunciation and audio quality are just fine. Some listeners aren’t accustomed to hearing a glottal stop. It’s not used as frequently in English as it’s used in other languages; but it’s appropriate. And I think the somewhat unpolished quality of your audio connotes authenticity, which draws in the viewer. Cheers.