Dear first of all, you must follow these steps to troubleshoot your problems in ur pc motherboard:-
a.Reset the bios
b.Check the power supply
c. Make sure you didnt over tighten the screws.
d. Make sure that the mb standoffs are only in the places where there are holes. if not it can short the
Motherboard.
e. Check for loose screws
f. Verify in the manual that the Power Switch is on the correct pins
g. Verify that the switch works. You can do that by finding the pins where the power switch connects and then take
h screwdriver and touch both of the pins (dont worry it will not shock you)
i. Reset all cards and memory
j. Unplug all fans, cables and cards from the motherboard. Only have the powerswitch, powersupply and cpu fan +
So memory hooked up. then try to post (this will eliminate the possibility of other things shorting out the mb)
k. As a last resort remove the motherboard from the case. and Only have the powerswitch, powersupply and cpu fan +
memory hooked up and try to turn it on. (this will elimate the possiblity of having the case short out the mb)
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If the mb turns on, but then turns back off.
1. Check the cpu, make sure its not over heating.
2. reseat all cards and memory.
3. check the powersupply.
4. check bios settings ( you may be overclocking the mb to high)
5. replace the bios battery (typicaly when it goes dead your computer gets stuck rebooting)
http://mobilesoftwareworld.forumotion.com/t13-how-to-troubleshoot-motherboard