Weird PC start up problem

[mikemikemi]

As the title says, I've got a weird start up problem that's only started this year.

Hardware: DFI Lanparty Jr X58, i7-920

Quick description: When the computer powers on it fails to reach post, power led is flashing, fans are spinning and the hdd sounds like it's trying to spin up but failing then spins down (and repeats). The computer can then only be powered down via pulling the plug at the mains. The seven segment displays on the board don't reach stage where they can post any errors.

I first thought it was my old Samsung drive playing up, since replacing it the problem has re-occurred, ruling out the drive as the problem.

Also, the problem is quite infrequent, only happens once every few weeks/months. Which makes it very difficult to recreate or diagnose. The last two times I've hit the power/reset button on the board and then it's powered up fine afterwards (although the last time didn't reset the bios), which leads me to think it might be the motherboard. This is still in warranty, however I don't know if they can diagnose the problem if it doesn't happen that often.

Any ideas?

Thanks.

[watercooled]

Any chance this is only happening with standby? I had a similar problem with my computer not wanting to wake from standby about 2/3 of the time, a motherboard swap fixed it.

[kalniel]

Could also be characteristics of your PSU at a particular load level - not providing enough juice on a 5v line or something for the given load. Do you have a lot of harddrives or anything plugged into the USB etc?

[mikemikemi]

Any chance this is only happening with standby? I had a similar problem with my computer not wanting to wake from standby about 2/3 of the time, a motherboard swap fixed it.

Not been using standby, although I'm not sure if it's associated but some times when I shut down the computer fans will remain spinning even though the pc looks like it's powered down. Pressing the power starts the computer as normal through post etc. and not as though I've put it into standby.

Could also be characteristics of your PSU at a particular load level - not providing enough juice on a 5v line or something for the given load. Do you have a lot of harddrives or anything plugged into the USB etc?

Only hard drives is a 1Tb Samsung F3 and 2 ssds not alot really. No usb devices other than the receiver for the kb and mouse. The PSU is a Seasonic 750X, which I did return for a new one when I first bought it. Makes me think I could be really unlucky and have a dodgy PSU?

[watercooled]

I'm guessing Mobo or PSU, but the only sure way of knowing would be to swap out parts. Do you have another known-good PSU to try?

[mikemikemi]

I'm guessing Mobo or PSU, but the only sure way of knowing would be to swap out parts. Do you have another known-good PSU to try?

Unfortunately not, now I wished I kept my last PSU as a spare. I might ask around a few friends to see if anyone has something I could borrow; although with the problem being quite infrequent it might take a while to rule it out. Pretty strange predicament, wishing my pc to break down more often.