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JohnElliott
April 29th, 2014, 04:33 PM
Powered up an IBM 5150 (the power supply is 240v, 130W) for the first time in years this evening. Shortly after I'd shut it down again, the power supply started fizzing and smoking. Once I'd yanked the power lead out and dismantled the PC and PSU, I found the blown component. Judging by the helpful guide (http://www.minuszerodegrees.net/failure.htm) at minuszerodegrees.net, it's a line filter capacitor.

http://i829.photobucket.com/albums/zz216/john-elliott-uk/Hardware/IMG_0140_zpsb394be5c.jpg (http://s829.photobucket.com/user/john-elliott-uk/media/Hardware/IMG_0140_zpsb394be5c.jpg.html)

The problem is that in the process of failing, it's managed to render part of its label unreadable.

So, two questions:
i) From what's left of the label, is it possible to work out the spec of a suitable replacement part?
ii) Are there any other components it would be prudent to replace while I've got the power supply in bits?

NeXT
April 29th, 2014, 04:51 PM
Well I can see another AC line filter hidden behind abit of cabling so if you are in there it wouldn't hurt to replace the other line filters.

SpidersWeb
April 29th, 2014, 05:48 PM
I think I used 0.1uF X2 on mine.
The machine will run without them though. I must say I'm quite guilty of often ignoring the line caps after a blow.

Replace both of them, you can see the second one in the picture, because it'll blow soon as well.

Edit: found this picture from after I had to go back in and replace the other line cap - 5150 220VAC
http://i83.photobucket.com/albums/j307/DrRabid/psu.jpg (http://s83.photobucket.com/user/DrRabid/media/psu.jpg.html)
(Yes the PSU got a wash afterwards)

modem7
April 30th, 2014, 12:35 AM
The machine will run without them though. I must say I'm quite guilty of often ignoring the line caps after a blow.
If I want motiivation to replace a faulty line suppression capacitor, I just read stats like the following.

http://www.minuszerodegrees.net/images4/Conditions%20on%20the%20AC%20line.jpg

SpidersWeb
April 30th, 2014, 01:31 AM
Oh, yeah that worked. RT and two XT's to do now.

modem7
April 30th, 2014, 02:57 AM
i) From what's left of the label, is it possible to work out the spec of a suitable replacement part?
I pulled apart my IBM 130W PSU. Visually, the filter board of it matches with the photo of your filter board, and with the filter board in SpidersWeb's PSU.
The subject cap in mine is a 0.1uF X2 250Vac type.
The second cap (SpidersWeb's "Should have replaced this") is the same, so you can look at your second cap for verification.

JohnElliott
May 2nd, 2014, 12:25 PM
Thanks for the advice and suggestions. The second filter cap was labelled 275v 0.1uF X2, so I obtained suitable replacements and got the PC powering-up again.