I've been trying to troubleshoot an intermittent problem for the last couple of months, and since the system was built from parts mostly recommended on Tom's Hardware, I'm hoping someone here might be able to help.
The original setup was:
CPU: an Intel Q6600 G0 CPU
MB: MSI P6N SLI Platinum motherboard
PSU: Aerocool ZERODBA-S620
RAM: 2x1GB of Patriot RAM (PDC22G6400LLK)
Graphics: EVGA 8800GT 512 MB
HD: 500GB WD5000ABYS
DVD: Sony/NEC AD-7170S-0B
The system ran very stable for about a year. It would then intermittently power-down instantly. The screen would go black, fans shut off, but the motherboard still has power (on-board LAN card lights still flash, etc). Hitting power button would start it up again, but quite frequently it wouldn't even make it to boot screen before powering down again. This is still my biggest problem that keeps on recurring. It doesn't seem to be related to heavy loads--it often happens at idle. It will sometimes go for hours without shutting down, sometimes it'll go down within 5 minutes of being turned on.
Memtest gave me an error at the same address every time I ran it. I tried setting DRAM options to 4-4-4-12, even 5-5-5-15 to no avail. Running system on only one stick of RAM seemed to greatly reduce the frequency of the problem, but replacing both sticks of RAM didn't resolve the issue.
I've updated the MB BIOS to 1.7, which also didn't resolve the issue.
I've recently installed a couple of tools to look at temperatures and voltages. One thing I noticed was that "vcore' would fluctuate from 1.14 to 1.34.
Any advice on what to look at next to make this machine stable again? Any help and suggestions much appreciated!!
More about :troubleshooting random system power downs
If you are getting errors in memtest at stock, you need to replace the memory sticks or motherboard. Sounds like the motherboard is the problem.
it's normal for vCore to fluctuate.
Your power supply is a Tier 4, not recommended. I suggest you get a good one.