HELP! Power supplies blowing up

[LTJLover]

I built a computer for a friend of mine back in September. About a month ago he told me it wouldn't start up. After looking at it, I put my extra 400W power supply in it and it was able to power up. I only turned it on briefly and saw that it had power before turning it off. I figured it was just another story of one of those cheap case supplies going bad. Well he took it home and fired it up to hear a loud pop and see smoke. Any ideas how to determine what is causing the problem without blowing more supplies? Has anyone had this problem or something similar?

P.S. After opening the first blown supply, the electrolytic caps on the 12V and 5V sides were blown.

AMD 1900XP retail HS/fan 400W PS
512MB 333 DDR
Gigabyte KT333 mobo (don't remember model)
Chaintech Ti4200 GF4
IBM 60GB 60GXP
SB Audigy platinum
Plextor 40x CDRW
Toshiba DVD ROM
Internal 250MB zip drive

 

[jihiggs]

i would test the computer with another psu at your house. it could be inadequate power in his house.

my computer is so fast, it completes an endless loop in less than 4 seconds!

 

[peartree]

There are a bunch of things that can cause a blown power supply. First is voltage surges or spikes, then overvoltage at his house, or bad ground and even a minor short circuit. Replace it with a known good ps and start checking. It's easy enough to check the first two and I'd have to bet on one of the first two. It all amounts to bad incoming power. Put a good surge protector (NOT a $5 sp!) on it or a UPS, if you have one, and try it again.

Then hope you haven't blown anything but the original power supply.

===> Never assume ANYTHING <===

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