Hi guys - first post. I did a lot of research about this issue I'm having but I'm still at a loss - so time to ask the experts
My computer randomly resets - I know it's not a software issue because it will reboot in Windows XP, Windows 7 (on another harddrive/partition), or even before I can enter the BIOS. I've tested my memory one-by-one and tested using different memory banks. I've reseated the CPU, applied new thermal paste and it's still running at 31 Celsius. I've disconnected all my SATA drives except for the one with the MBR. Checked the motherboard for faulty capacitors or leakage - but nothing there.
Sometimes I hear the PSU turn off completely and restart the power cycle. Sometimes it'll reboot without any fluctuation in the power (ie the power supply stays on.) Here is a description of my guts:
Gigabyte P35-DS3L mobo Firmware rev. F8a
Intel e8400 CPU @ 3.00 ghz stock speeds/not overclocked
Zalman 9500A-LED 92mm copper CPU fan
2x Zalman ZM-F3 120mm case fans
2x 2GB G SKill 8500 memory sticks (tried one stick alone, tried 2 in 0&2 banks and 1&3 banks)
2x 1GB OCZ PC2 6400 memory sticks (for testing - makes no difference - still getting reboots.)
MSI N250GTS Nvidia GTS 250 512MB PCI-e video card.
XG Vortec PSU PSVO-600 600W ATX12V PSU
2x Hitachi 1 TB drives.
2x Seagate 1.5 TB drives.
What really has me stumped is that it will sometimes reboot 3 times as soon as I start the computer up and at other times, the computer will stay on for hours before randomly rebooting. This happens when I'm surfing the internet, playing a game, watching a movie - doesn't matter. My CPU stays pretty cool at 30 degrees to 45 under load. My GPU is about 50 degrees to about 80 under load. I ran memtest86 overnight an no errors - but I've also tested the memory in different configurations and even tried another set of spare RAM.
Mobo looks fine - no leaky capacitors or anything. I reset the CMOS battery but no dice. Reset the BIOS to optimized config and it still happens. I do have to modify the voltage to my RAM because it doesn't receive enough juice at the default bios settings and I get a BSOD. Other than that - everything is at defaults - no overclocking.
Any idea what it could be? I ordered a Corsair PSU which should arrive in a few days so I can test the PSU then - but my current PSU seems to be working fine otherwise. The rails are passing what they should... the northbridge seems a little hot to the touch, but I think that's normal - not sure.