Motherboard problem

[#1]

I have a problem which I suspect is a motherboard failure.
It's am Abit KN8 SLI
\when I try to boot up, lights come on and fans start but each time after precicely 4 seconds it all closes down
I tried a new power supply but the same thing happens.
I suspect that it's the motherboard
Can anyone please advise what other causes if any are likely?
Thanks

[#2]

Try changing the CMOS battery before you bin the motherboard!  It's on the motherboard and about the size of a 2p piece.  You may have to set the BIOS back to defaults after changing it (you may be prompted to do that on boot up).
If you don't want to take the top off you can ge someone to do it for you.  A new battery costs about £3 - much cheaper than a new mobo and worth trying first!

[#3]

4 seconds is a bit short for anything overheating but do you get any BIOS beeps from the speaker as these can be interpreted here.
I would also suggest looking at the processor heatsink making sure it's properly seated but again 4 seconds is a bit quick for an overheat.

[#4]

Sounds like a motherboard - but you could try disconnecting peripherals like disks and video card etc,
in case some kind of surge is causing the CPU to shut down.
Also you can give it a visual inspection for any shorts - and as a last resort remove dust etc with the hoover.

[#5]

Sounds like a problem I had yesterday.  I recently put in some new memory and one of the banks had worked loose.  Once it was re-seated everything was back to normal again.

[#6]

4 seconds would be long enough if the cpu fan wast working correctly as most mbs shut down if the fans not going to save the cpu. A corrupt bios would do it as well.
clear the cmos this is normally a jumper or remove the battery for a couple of mins removing the power. Remove any thing you can like floppy, hd,printers and see if it fires up

[#7]

Thanks to all for help and suggestions
Well I tried everything
Changed the cmos battery
removed the fan and heat sink
vacuum cleaned all round
cleaned and used fresh heatsink thermal paste.
Same problem ocurred
disconnected HD's, DVD's etc
Still the same
closedown after 4 seconds each time
I'm wondering if there could be anything else I haven't tried
I tried my usual sources for a 939 socket motherboard and no one seems to stock them anymore
I tried to contact Abit who never respond to the phone on any of their numbers
Tried their USA number but was put on hold eby their automated system
They ignored my emails so I'm wondering if they've gone out of business
Next questions would be
Is it really time to bin the motherboard or is there something mre I could try?
Where could I find a 939 socket motherboard
Would the processor fit any other sockets?
Thanks again

[#8]

http://www.pcupgrade.co.uk/category.asp?categoryid=271
http://www.novatech.co.uk/novatech/products/a836x1y0z1p0s0n0m0
Regards,
Neil

[#9]

Have a try here http://forums.hexus.net/abit-care-hexus/

[#10]

I have recently had a PC that would do the same. The power switch on the front was sticky, so it would power up, and because the motherboard thought the switch was still pressed, it would shut down again. Can you swap the reset button with the power button?

[#11]

Remove any USB  that plugs onto the board as that can short out. The power button is a good point if you can find were it connect to the MB remove the wires and short the pins quickly with a screw drives this will ensure it doesnt reset. Take care with this that its not an old MB which has the switch that handles mains voltage

[#12]

I would not recommend using a screwdriver on the power pins as any slip could short the mobo. As stated above, just swap the reset and power connectors on the mobo to check if it is the power switch (and remember to use the reset switch to power on/off).

[#13]

After a quick search Scan stock THIS like stated above.
Don't know what CPU you have currently but perhaps this is a good time to change to an Intel Core duo or Quad even? 

[#14]

After all that I tried taking out the memory altogether and it doesnt shut down
I tried different memory and different sizes but it still cuts out after 4 seconds whatever I put in
So now I wonder if theres anything else to be done or if I need to get another motherboard
Why should memory stop it working?

[#15]

Hi,
yes its a good one. I took it out of a case that I bought brand new recently