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!
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.
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.
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.
""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 ...
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.
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.
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.
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!
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.
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.
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 !
@@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 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.
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.
@@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.
