Power Supply Troubles

[made_of_asp]

Hi,

Recently I was browsing the net and my computer locked up - I restarted it and it wouldnt boot to Windows. The PC speaker was making a myriad of beeps. So I turned the computer off - and a second later it turns itself back on.

I figured it was a power supply. It is a cheap one - some no-name brand Hairong 400W (supposedly).

Since then, I tried another power supply in the system and it worked. Then I tried the one that supposedly failed and it worked fine.

What could have caused this?

I also noticed when opening up the computer that a cable got stuck in the video card fan and was jamming it . I unstuck it, but I realy doubt that a stuck video card fan can cause the system to turn itself on after it has been shutdown. The video card works perfectly. The whole computer works perfectly.

System:

Athlon XP 2000
256 DDR RAM
Gigabyte Motherboard [KT600]
1 Hard Disk
1 CD-RW Drive
ti4200 video card
SB 4.1 sound card
2x case fans

I got so scared because of the shutdown, i immediatly ordered an Antec power supply . I have bad luck with generic Power Supplies: 1 of my PSU's keeps on turning the computer off for no reason, 1 had a fan failure.

The Power Supply gives out ok power (i guess) althrough i've seen better: 12.5V for 12V rail.

Do you think it was the PSU or something else? My conclusion is that it just overheated. The PSU, btw is a few weeks old.

Thanks for any help

[Electroman]

You might have seen my posts this week about troubles with my PSU, I was also using a 400W one which casused my PC to just switch off now and again. Before that I had troubles with a PSu about 4-5 months ago where one day my PC wouldn't turn on, when I pressed the on button it started then less than a second it would go off and begin to start again, was horrible cos its like flicking the switch on & off really fast. Eventually it did start if I unplugged it for a few minutes each time before I booted. That PSU was 250W or 350W and I replaced it with a 400W which as I said is now replaced but this time with a 520W and its running fine now .

Just shows theres several ways a PSU can fail. BTW the first PSU is now in my spare PC and is working fine, its never done the jumpy start thing on that one . My PC is a real power hog though .

If you check out the threads I made about the PSU then you'll see I gave two links to some PSU calculators that will work out what size you should use .