Mobo or PSU issue?

[pkilway]

I've had this psu for over a year. It ran my last setup like a champ (DFI NF4 DAGF, Opteron 175, 2GB Dual Channel OCZ DDR-400, same HD's, same DVD's, same X-Fi). I was even able to overclock my Opteron 175 to 2.7Ghz stable.

In July I rebuilt my system (nothing is currently overclocked):

Case: CHENMING 501AWU-F-0
PSU: Antec True Power Trio TP3-550 PSU
Mobo: MSI P43 Neo3-F(BIOS 1.0)
CPU: Intel E7200 Wolfdale with ARCTIC COOLING Freezer 7 Pro w/ MX -2 Thermal paste
RAM: Patriot Extreme Performance 4GB (2 x 2GB) DDR2 800 (PC2 6400) Dual Channel Kit set to 4-4-4-12 @ Default voltage
VIDEO: MSI NX8800GT 512M OC PCI-E
AUDIO: Creative Sound Blaster X-Fi XtremeGamer
DVD RW: ASUS DRW-1608P IDE DVD Burner
DVD: ASUS DVD-E616P3 IDE DVD-ROM
HDD: RAID 0 - 2 x Western Digital Caviar SE WD800JD SATA 3.0Gb/s
HDD: Western Digital Caviar SE16 WD6400AAKS SATA 3.0Gb/s
MONITOR: Samsung 226BW Black 22" 2 ms Widescreen LCD Monitor
ROUTER: Linksys WRT54G Wireless G Router
OS: Windows XP 32 Pro SP3

When I built the system in July I ran Orthos for 10 hours, with no errors. I ran Memtest86 (the DOS based program) for 10 hours on the memory to test it, no errors.

I've not witnessed this, but it has happened to my wife, twice.

While using email about two weeks ago, our computer mysteriously turned off. My wife was pretty upset that she lost an email that she had been typing out, it had taken her 30 mins (she's a teacher and was doing lessons plans for the next day). Then again yesterday she said while browsing the net it did the samething.

One second the pc was on and working, the next - black screen and silent. She described it as if someone unplugged a TV - or computer.

Last night I tried to recreate this problem. I ran Orthos, Prime95 and looped a virus scan for a few hours (Orthos and Prime95 continued to run for a total of 10 hours at the same time). Orthos and Prime95 both reported no errors. Realtemp showed my cpu cores never broke 44C.

Is this a symptom of a short in the psu? Faulty mobo? I double checked all my mobo connections, made sure that there wasn't a accidental connection between the mobo circuitry and any piece of metal. I can't recreate the problem. Anyone help me out with a clue as to what could be causing this?

[Tazz]

Well if it was a hardware issue (mobo, video, or something like that), chances are it would BSOD. Seeing that it's simply shutting down, I would look at swapping the PSU out with another to see if it solves the problem.

[pkilway]

kk, I'll look into doing that very soon.

[dragoncdf]

I had the exact same thing happen to me awhile ago and it turned out to be the psu. The 4 pin 12v connector burned luckly the motherboard was ok. So I would change the psu asap.