PS testing, poof and blip

mikeford

Diamond Member
Jan 27, 2001
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One of my OLD, W98 systems stopped booting a year or so ago, so I turned it off, unplugged etc and put it aside. Finally last night I decided to fix it.

Opened up the case, disconnected all the drives and mother board from the power supply, plugged the PS into one of my fancy new $13 from China testers, plugged in the AC cord, and flipped the power from 0 to 1.

Power came on, tester back light was on, but a cap in the PS blew making about a ft sq cloud of something, so I turned off the power and disconnected everything. Old cheap A Power Ultra Edition P4, now smells like blown cap, but no visual damage, assuming its toast, its now a pile of parts most headed for the recycle bin.

Fortunately I have a new still wrapped in the bag I bought it in replacement PS. Unfortunately its the same model and brand as the bad one. ;( Still new and all I thought maybe it would last a year or so at least, and installed it in the PC case. Plugged it into my tester just in case it had issues, plugged in the AC cord, flipped the switch, and blip.

All power seems to come on very briefly, then nothing but the 5v standby. I plugged in a drive to give it some load, and tried my PC Cooling tester with the resistor pack, no response at all, but I am thinking maybe one of the other busses needs a load to make it work so I am thinking of plugging it into the mother board and giving it a try.

As long as the 5v standby power shows green on my tester, turning the PS 0/1 power switch off and back on does nothing. If I wait til the 5v completely drops, I get the blip of power on all the busses.

Should I skip it, or plug in the mother board and try it?
 

mikeford

Diamond Member
Jan 27, 2001
5,671
160
106
I put it aside and started working through my junk box, of "maybe" not junk, parts pulled from old systems when scrapping them.

I made smoke. Testing a PS with my cheaper $7 10 LED tester, all green and started fine, plugged in a hard drive connection and that looked fine.

BIG MISTAKE coming ...

I didn't unplug the drive power connection before plugging in the square 4 pin, and I think that shorted something or allowed some issue within the power supply to kack (this is the old ps that fan kept running on when PC was switched off). Good news I am sure PS is bad now.