my setup:

case: cooler master atcs 840

motherboard: gigabyte ep45-ud3p

cpu: intel's e8500

ram: 4g kit 800 mhz kingston

psu: corsair tx-850w

hdd: 1xtb w.d

graphics card: gtx 260 o.c

*i don't know for sure if it's my motherboard or my case (switch)*

problem: when i press "power" the lights on my motherboard and the front panel (case) led's lights up as normal, as well as the case fans turns on as normal.

wait 1-2 seconds the led lights on the front panel and on my motherboard turns off, as well as my case fans.

wait 2 seconds everything turns on as normal.

q1: what could be the problem?

q2: what can i do to fix it?

my computer does the same thing at times. I have a totally different mobo and case. This isnt a problem as this has been happening to me for two years now. 

I think it's the motherboard testing the bios settings or something like that before it does anything else. I have a Gigabyte P35-DS3P and if I change a bios setting or shut off the power supply, it'll turn on for a brief moment and then shut off for a second before turning on again when I hit the power button for the first time.

try this link... http://www.tomshardware.com/forum/246825-28-computer-turns-seconds-shuts


someone else is having a similar problem, maybe the solutions the same.

also yous should try to short the header