machines powers on for 2 seconnds then shuts off.

englishpremier · 20 Aug 2006 at 12:02

I have a spare machine that I put together, its nothing special 2200xp 512ram 80gig hdd etc..

Now i built it but did have a psu so i used my Hyper 350w to install windows etc..

I took the machine round to a friends to use with his spare psu but the machine now will not work. Basically it powers on (all fans spin etc.. ) then after about 2 seconds powers itself off.

It does this with a generic crappy psu and an Antec 350w psu. I can't for the life of me think whats wrong.

Any ideas?

allllec · 20 Aug 2006 at 12:06

Disconnect all Chasis fans, sounds silly but ive had many break and short, so the PSU just refuses to boot.

Also when it does come on do you hear a click from the psu?

tim_enchanter · 20 Aug 2006 at 14:04

Also check the CPU cooler is seated on the CPU properly, check the temps and voltages in the bois if you can get that far.
I've had that happen after moving a pc before, the mobo shuts down after seconds as the cpu gets to hot.

allllec · 20 Aug 2006 at 14:09

also, make sure the cpu fan power cable is securley on the power port on the mobo, if the rpm appears to be 0 the computer might refuse to boot

englishpremier · 21 Aug 2006 at 16:18

the heatsink is fine and so if the fan, even if the cpu fan wasn't on, it would take a long time to reach shut down temp..

Gonna have a rebuild tonight and see how it goes.

acharris · 21 Aug 2006 at 18:18

Hi, actually on some mobo's it is not the temp that causes the PC to shut down, but the fact that the CPU Fan header don't read any RPM from the HSF and then the mobo thinks the fan is not working and shuts down to prevent overheat.

Actually with a CPU fan not working I have seen a XP2400+ from turn on to the bios screen goto 80+ degrees in 20-ish seconds on a warmish day, so can get hot quite quick sometimes.

VeNT · 21 Aug 2006 at 18:26

acharris said:
Hi, actually on some mobo's it is not the temp that causes the PC to shut down, but the fact that the CPU Fan header don't read any RPM from the HSF and then the mobo thinks the fan is not working and shuts down to prevent overheat.

Actually with a CPU fan not working I have seen a XP2400+ from turn on to the bios screen goto 80+ degrees in 20-ish seconds on a warmish day, so can get hot quite quick sometimes.

SHUTDOWN ON CPUFAN FAIL is the option your thinking of, and yes
if your CPU fan header/fan/whatever is faulty and not giving the motherboard the details it wants then the system will shut down.

Steve09 · 21 Aug 2006 at 19:14

You have put the power buttons adaptor onto the motherboard wrongly.

I did this, and exactly the same things happened. If you switch the adaptor the other way round on the motherboard connecter, it will work.

Steve

englishpremier · 23 Aug 2006 at 10:29

stevechapman said:
You have put the power buttons adaptor onto the motherboard wrongly.

I did this, and exactly the same things happened. If you switch the adaptor the other way round on the motherboard connecter, it will work.

Steve

the power switch adaptor could be the wrong way round but if thats the case i never would have been able to have it on long enough to install windows, which I did when i first built the machine.

The computer then was taken a friends who when he plugged in a psu, would only stay on for a few seconds. HSF all fine, and the psu's both work. The computer is running ECC ram is that would make any difference, the motherboard does support it and as mentioned I did previously install windows no problem.

englishpremier · 24 Aug 2006 at 13:24

as mentiond problem was with the fan headers on the board. cheers for the help.