New PC switches off during bootup

Bustabit

Junior Member
Apr 13, 2003
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Just built 1st PC with ASUS A7N8X mobo. press power on - cpu, case & graphics card fans startup, as do hard drives. everything whirrs for about 5 seconds and then it just shuts down. Any ideas?
 

EeyoreX

Platinum Member
Oct 27, 2002
2,864
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Bad RAM or inadequate power supply are my first two guesses. Try testing with one stick of RAM (or a different stick if you have only one) see if that fixes things. Also, what is your PSU? If it is not a good one it might not be providing adequate power to your components.

Another thing that comes to me is if your heatsink/fan is not properly installed. Make sure they are or your motherboards CPU Protection scheme might be shutting down your PC to save your valuable parts.

Try reseating everything and make sure your components are tight/seated correctly.

Good luck and let us know if you need any other help.

\Dan
 

Bustabit

Junior Member
Apr 13, 2003
3
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Dan
Thanks for your suggestions. I'v tried reseating the CPU, heatsink and fan & memory. All seems OK but still no success. Unfortunately I have only one stick of RAM so can't try another. The manual says that there will be POST beeps if it has problems with the memory but the machine shuts down before any beeps/messages at all so the problem must be pretty basic.
Any more ideas would be most welcome!
/Nick
 
Apr 12, 2003
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It is highly recommended that after you first insall a new motherboard you clear the CMOS. Read in your manual how to do it. It is usually by moving jumper.
 

Bustabit

Junior Member
Apr 13, 2003
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Done that too! I've also checked the case alarm jumper which I see can also prevent bootup
I think I will have to admit defeat and get the dealer to test the board & cpuThanks for your interest and help
 
Apr 12, 2003
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When that stuff happens it is true it could be the mobo, ram, cpu, PS, etc.. but if I had to pick one as defective it would most likely be the CPU
 

silent tone

Golden Member
Oct 9, 1999
1,571
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My Asus board did that when I was starting to overclock. I think I set the FSB too high and then it started that. Clearing the CMOS did the trick. Although it took several tries for the clear to take effect.