PC shutting off

[BritishBeef]

Hi there,

I've posted this problem to the thread before but there are a few updates to the info:

I have a fairly new Athlon XP3000+ Desktop which I bought. I had a problem after a month of it running fine where the 350W power supply died. I returned the PC and they replaced the PSU with a new 400W. The pc ran fine for a couple of months, but now it keeps randomly powering off. It's not going through a shutdown, it just powers off. After this happens, if I immeadiately power on the PC again, it powers on and the HD's spin up but it powers off again within a couple of seconds. If I leave it for a couple of minutes it powers up fine and will run well for hours or sometimes days 24/7 until it powers off again. Any Ideas what could be causing this?

*Update*

Since this original post, I have run this PC for a good few months woth only a couple of instances of the power off problem. I just left it for half an hour and then it always booted up fine and would run for hours. In the last few weeks however it has been happening every couple of days. I have been monitoring the temperatures and there doesn't seem to be a correlation between processor or motherboard temp when it shuts off. eg. I can run a graphic intensive game and the temps will shoot up but it runs fine, on the other hand I can boot up from cold and it will power off after 20 minutes with CPU at about 45C and motherboard at about 27C. Fans seem to be running fine and I have 2 extra fans installed. There doesn't seem to be any power surges etc. Nor does changing plug sockets help.

Any help greatly appreciated.

My PC specs:

WinXP Home

Athlon XP3000+
Codegen 400W PSU
1 Gig 333mhz DDR ram
Seagate Barracuda 120 Gig HD
Maxtor 40 Gig HD
Gainward Geforce 4 ti4800se 64mb
Soundblaster Audigy Player
DVD rom
CDRW
Enermax case fan
MRI PCI ADSL modem
56K modem
2x variable speed case fans

Regards,

Geoff.

[brad]

Sounds like it could be the internal breaker/reset in the Power Supply. I had one that did that. It was always random.
brad

[allaboutpc]

When you get the chance read our power supply troubleshoot article at
http://www.ultimatepcrepair.com/news/18.html

Rebooting and shutoffs are commonly caused by the power supply.
Hope this will be of help