PC shutsdown after 10 seconds

[UseNet]

I have a PC that after starting, shutsdown after 10 seconds, even before
entering the BIOS screen. I must turn the main power in back off for at
least 10 seconds, then back on to even get it to power up for the next bout.
I have tried replacing powersupplies and same results. Is the motherboard
done? Any other ideas?

Thanks

CR

 

[DaveW]

It does sound like your motherboard has a fatal thermal fault.

 

[Paul]

I have a PC that after starting, shutsdown after 10 seconds, even before
entering the BIOS screen. I must turn the main power in back off for at
least 10 seconds, then back on to even get it to power up for the next bout.
I have tried replacing powersupplies and same results. Is the motherboard
done? Any other ideas?

Thanks

CR

An overheating CPU might be enough to shut it off. Check that the heatsink is
firmly clamped to the CPU, and that the CPU fan is plugged in and running.

Another kind of fault, is with the Vcore regulator on the motherboard. If the
electrolytic capacitors are bulging or leaking, a failed capacitor can cause
the Vcore regulator to shut off. But that might not kill the power entirely.
It can require cycling the power, to try again.

I think I'd concentrate on the CPU cooling first, and see if that is the problem.
If you have some replacement thermal paste, like one of these two, you can
disassemble the CPU heatsink, remove all thermal interface material, then
apply a thin coat of paste. Reassemble, making sure the fasteners on the
heatsink are secure, and that the fan is plugged back in. Then power up the
computer and see if it runs for longer than 10 seconds.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835100007
http://www.newegg.com/Product/Product.aspx?Item=N82E16835100009

Paul

 

[John McGaw]

I have a PC that after starting, shutsdown after 10 seconds, even before
entering the BIOS screen. I must turn the main power in back off for at
least 10 seconds, then back on to even get it to power up for the next bout.
I have tried replacing powersupplies and same results. Is the motherboard
done? Any other ideas?

Thanks

CR

In a similar situation, the first thing I'd try would be resetting the
CMOS. There is always a chance that some critical setting got changed
that is preventing a proper startup. Really nothing to lose at this
stage, anyway...

 

[larry moe 'n curly]

I have a PC that after starting, shutsdown after 10 seconds, even before
entering the BIOS screen. I must turn the main power in back off for at
least 10 seconds, then back on to even get it to power up for the next bout.
I have tried replacing powersupplies and same results. Is the motherboard
done? Any other ideas?

How good are those other PSUs? What are all the brands you've tried?
Do they work with other mobos having comparable CPUs and graphics
cards, i.e., draw at least the same amount of power? Two PSUs of the
same power rating can vary by over 2:1 in what they can actually put
out. See www.jonnyguru.com for details.

I would check for a card not being plugged in all the way, especially
the graphics card, or a short between the mobo and case, especially
around each mounting hole and at the corners (cases and mobos
sometimes bend enough to touch).

Are any capacitors (upright cylinders covered with shrink wrap) on the
mobo bulging or corroded on top? If so, they need to be replaced,
possibly along with the MOSFETs or diodes near them. See www.badcaps.net
for more information on this.

 

[Raymond Martineau]

I have a PC that after starting, shutsdown after 10 seconds, even before
entering the BIOS screen. I must turn the main power in back off for at
least 10 seconds, then back on to even get it to power up for the next bout.
I have tried replacing powersupplies and same results. Is the motherboard
done? Any other ideas?

This seems a little familiar - have you tested the power switch with a
multimeter?