Computer sometimes doesn't boot
 

I recently encountered a strange problem with a new build that happens occasionally. After sleep or shut down, when I turn it on, everything powers up for a second and then shuts off...then it tries to power up again automatically. This happens a few times until eventually it stays running until either the system starts up or it get stuck on a blank screen. If that happens, I have to turn off the power supply altogether.

Any thoughts? I've also started to notice that the fan noises aren't as consistent anymore, I can hear more "powering up and powering down". Maybe that has something to do with it?

OCZ Fatal1ty 700W PSU
Gigabyte P55-UD4P
OCZ Obsidian 4GB DDR3
Core i5 on stock cooling, not overclocked
Windows 7 Ultimate

Thanks!

what bios version you using mite clear up some issues also check chipset drivers for MB

usally its a bad driver hang suspend mode

other may have a bad CMOS battery

+++

Get the latest drivers first, and then check for a bios update.

Was using F3, now I'm on F5, problem still persists.

Tried and eliminated a bunch of possibilities:

Tried each ram individually, memtest86 okay, Intel Burn Test okay.
Unplugged unnecessary devices, problem still there.
Remounted motherboard, rewired to ensure no shorts (although I can't rule that out unless I run it outside the case, but my room has carpet)
Drivers updated

I suspect it's the power supply, but I don't have a spare to test. Right now 50% of the time it powers on normally. 25% it powers on for a second, powers off, then powers on normally (after 2-3 times). 25% it powers on for a second and stays off longer.

This is now happening in normal shut down as well as in sleep mode.

Any thoughts? Is this more likely to be the motherboard or the PSU? The PSU is new too.

question are you using 2 moniters on that system?

if are need to set primary for the desk top unit

Check at tweaktowns gigabyte official forums you can ask there to

what you describe sounds like the gigbyte board may not be set totally right.
Go into cmos and see if a warning comes up right away about cmos bios settings.
Sounds like its doing a self test on start
in gigabyte board i have yur cmos cpu fan settings for automatic and manual settings to.
auto goes as load and manual is on full always.

I have seen similar behavior before, but the machine works fine.

After pressing the power on this machine will turn on for about one second, then turn off for a second, then power on and boot like normal.

The only thing that matches your build is the OCZ PSU.