Occasional no-POST, Voltage/PSU Problem?

[Saka]

Recently I built my new computer with:

Intel e7200 Wolfdale 2.53GHz (@3.53GHz, 1.23V stable for 7 hours on Orthos)
Foxconn G33M-S Motherboard
4GB Mushkin 996580 (@1013MHz, 5-5-5-18 2T, 2.09V)
Zotac 8800GT amp! edition
Seagate 7200.10 250GB HD
DVD-RW Drive from Lite-on
and the Case/PSU @380W (I hear generic PSU's aren't too good, but also I heard that this one was actually reliable.)

Anyways, my system seems pretty stable (full memtest pass, 7 hours stable on Orthos, stable playing Oblivion), but occasionally when I turn on the PC, I don't get a post. No beeps, nothing, no keyboard light up. The fans spin, the orange LED from the video card is on, but no post. I thought it might have to do with not feeding enough voltage into my CPU/NB, or potentially my PSU being really low quality. Any idea what the problem could be? Thanks in advance.

PS - First time overclocking/building my computer from scratch. All the information I've learned from doing it has really enlightened me to the benefits of building/overclocking my own PC. A few guides over here at TPU have really helped me out, so thanks for all the help in building/overclocking my computer too.

 

[jbunch07]

The PSU is the most likely problem.
A PSU is the most important piece of hardware in your system, don't skimp out on it.

 

[Namslas90]

Check for BIOS updates, Motherboard/chipset updates. If that doesn't solve the problem I would get a power supply with more power. 380watts with all that is underpowered. I had a AM2 rig with 2gb Ram, DVD, CD, and four HDD's with a 350 watt PSU. I put in a VGA card then all sorts of things started happening; No post, HDD crashes, S.M.A.R.T. errors ETC. Upped the PSU to 500 watts and all the DEAD HDDS worked all of a sudden and all the other problems went away. WIth that 8800 I would go for something that supplies the Amps you need on that 12+ Rail.

 

[Saka]

Thanks a lot guys, I'll look into updating the BIOS and maybe underclocking my currently stable system(yes!) until I can nab myself a more reliable power supply.