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AT PSU in 5160 XT

bettablue

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I have been working with my XT computer. The PSU is running at 20% below specs on all outputs lines. Then I also found that the PSU actually came from an IBM 5170 AT.

Does anyone here know where I can get the 5170 power supply schematics? Second thought: does anyone here have an XT power supply I might be able to purchase reasonably? Either way will be OK with me. With the correct schematics, I can easily repair the power supply. Repair parts are not hard to get.

Last thing. I still don't know if the PSU is the only problem with the XT. I suspect that the PSU is only one problem among 2 or more, and the hard disc is also need of a replacement.
 
Are you sure it's a 5170 PSU because I thought the fan outlet and mains plugs are in different locations?
From memory the rear exhaust is more centered.

Finding a replacement supply shouldn't be hard. Clone makers kept using the 5150/5160 PSU case design in full sized desktops up until the 386.
 
Is there an IBM part number on the PSU, I'm looking at an old 5170 PSU i have here and it's different to the 5160 psu and wouldn't fit the 5160 case. A PSU from a 5162 would fit in a 5160 or it might be some other "clone" PSU.

I've not seen any schematics around.

I have been working with my XT computer. The PSU is running at 20% below specs on all outputs lines. Then I also found that the PSU actually came from an IBM 5170 AT.
 
Thank you for posting the link. And to answer the other questions, the power supply does not appear to be manufactured by , or for IBM. Once I open the unit, I should be able to tell for sure if it was made by IBM or not. Till then, I'll be heading to the electronics store! with PSU in hand along with the schematics, to see if they can identify the PSU. I'll work accordingly from there.

Thanks again

It's all moot though, because I do have an extra PSU we could try. I just don't trust that it is working properly.

Hi Bettablue! I have this schematic for the XT power supply if it will help you.

View attachment 13353View attachment 13354
 
I'm not sure IBM ever made the power supplies.

Those schematics wont necessarily match your supply board, but an experienced electronics repair company should not have trouble diagnosing the fault - power supply designs for everything are usually all built around one of a few principles. I took my 5151 in and the guy diagnosed a bad power supply transistor and replaced it. But I purposely tracked down somebody who did computer repair in the 1980's. Annoyingly it did take him 2-3 weeks for 2 hours labour :(

It will be a lot cheaper and less time consuming to buy a replacement off ebay, especially since it just sounds like a clone supply.

I buy replacements when available, and if not available, I custom mount modern ATX supplies in the old PSU case. Unless the fault is obvious - e.g. blown caps, I put it in my 'later' pile for when I'm older with more time and a good scope. At some stage there will be so few, rebuilding will be necessary, but right now there is still a supply of supplies ;)
 
I should mention that the schematic I provided is for the original 5160 power supply. If the one you are working with is an aftermarket unit the print likely won't match it.

My original 5160 power supply was defective. I didn't have the schematic then, and I ended up installing a more modern supply inside the housing of the original much like SpidersWeb is talking about. You simply can't tell without opening the power supply up, and I feel more confident about running the machine hard. I have a collection of computers, but this XT is my favorite, and it's on nearly every day. Power supplies and hard drives don't age very well really, but if the power supply blows, it can damage other parts of the computer.
 
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Thanks again. Everything at this point helps.

I have the power supply out right now. It has an IBM Model: AA12156 with a part number 6447192. When I look these up, the results come back as an XT power supply, so there shouldn't be any problem. I don't know where I got AT from. From what I can tell, the schematics look right. I'll go over them and see what I can do in the next couple of days.

Thanks again for the schematics, and to all of you for your advice. I'll post the results of the PSU repair when I'm done. I might even have some photos to show how to check and repair these units for future reference.




I should mention that the schematic I provided is for the original 5160 power supply. If the one you are working with is an aftermarket unit the print likely won't match it.

My original 5160 power supply was defective. I didn't have the schematic then, and I ended up installing a more modern supply inside the housing of the original much like SpidersWeb is talking about. You simply can't tell without opening the power supply up, and I feel more confident about running the machine hard. I have a collection of computers, but this XT is my favorite, and it's on nearly every day. Power supplies and hard drives don't age very well really, but if the power supply blows, it can damage other parts of the computer.
 
The 6447192 may be the PSU mainly used in the 5162. The main difference between this and the typical 5160 PSU is that this one autodetects 120/240VAC and can be used in Europe without a step transformer.
 
Hello
I have the same PSU ( Model and Part Number ) to repair for my XT.
Is this only a 110V Model or 110/220 Part ?
Have you repaired this part ?
Thanks and Best Regards
Pierre
 
Thanks for all of the input. I bought a power supply for a 5160 and now all is well. It did take a bit of fiddling to get it working properly, but it does work.
 
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