Athlon II X4 640 - Quad Core/3.0ghz
4GB OCZ 1066 RAM
ASUS M4A785TD-V Motherboard
Western Digital 320Gb Black SATA 3.0 HDD
MSI GT-240 Video Card (1GB/GDDR5)
Windows 7 Ultimate
Now, I have two identical systems like this. All parts are the same. One runs exceptionally well. The other...not so much. It constantly reboots, BSOD's, games hang, windows services and programs fail to start or error and close. I have tested and replaced the memory and the video card (both found to have failed). I have clean installed Windows every time I have replaced a known bad part.
I have run diagnostics on the CPU (temp, fan speed and stress) using BurnIt. 8 hours straight with no issues. However, try and play a game or let it sit idle for too long and an issue will emerge (BSOD or reboot). Tested power supply by pulling the PSU, opening the case and inspecting the capacitors on the inside for damage or the tell-tale smell of ozone but found nothing. Pulled out my trusty multimeter and tested the power from the molex connectors. Power is stable and within spec. I have reseated all the parts and even pulled the motherboard out and double checked the brass posts to insure there was no short or loose connections.
The only other thing I can think of is that the mother board is bad. It is now past its return window and ASUS will not RMA it without the serial number which is only located on the box which was thrown away some time ago (silly, I know - ASUS for not placing the serial on the actual product and me for throwing away the actual box).
So, I am out of troubleshooting ideas. I would really like a tool that could test the motherboard. If anyone has any suggestions, please post them. If you have any further tests you could recommend, by all means inform me.
Simply inspecting the PSU is not the same as eliminating it....; the gpu draws quite a bit more power from the PSU when gaming that might not show issues with you simply measuring the outputs on a DVM....
If two identical systems, changing the PSUs between them will allow it to be almost definitively ruled out....
If the system still hangs, swap gpus between them....; if it still hangs....
I'd also check mem timings, voltages, make sure you are not runnning too tight of timings on one system over the other, even with identical MBs, each might allow a little more/less of a mem overclock....; try default timings, with a single stick in first slot.
If it still hangs/BSOD, then really only the MB is left.
Ill try swapping the power supply. The GPU swap not a bad idea and ill give it a try but I think its a non-issue. As for the memory, I have been on the OCZ boards talking with engineers fro the better part of a month. I think we have applied about all the tricks and tips for memory that exists.
I completely agree with your final statement. It seems I have eliminated every other option, but I will go through these last few steps and see what happens.