I have an older PC system that I gave to my partner. The system was built probably in 2010 (can't remember exactly, .) The motherboard is a Gigabyte GA-P35-DS3P, PSU is an Enermax Liberty 620W. It has been working fine since it was built.
Earlier this week she started it up, all the fans came on, and then it abruptly shut down after about 10-20 seconds, restarted, shut down again, etc. No beep codes, not long enough to get to the BIOS screen, let alone to the boot screen. We had had a power outage a few days previously so I immediately thought it must be a power problem. I did all the simple things such as making sure the power cord was fully plugged in, checked the UPS, changed outlets, etc. This made no difference. I tested the voltage of the PSU (24 pin connector and 4 pin 12-V connector) with a multimeter, everything tested out fine. I checked all of the internal cable connections, reseated the memory, still had the same continuous start up/shut down cycle problem.
The system had four sticks of Mushkin XP2-8500 1 GB memory. I removed all but one of the sticks and, voila, system booted up. The motherboard is supposed to be dual channel, but won't start up with 4 sticks, won't start up if there is a stick in slot 1/3 or 2/4 as required for dual channel use. I can put memory in slots 1 & 2 and the system starts up fine, shows 2064 MB of RAM in BIOS. I can't remember the other combos I tried but as far as I can tell, all four sticks are good....
So, is the motherboard on its way out? Could memory slots 3 & 4 have fried somehow without causing any more damage to the mobo? Anything else I should be checking?
Puzzled in Colorado...
Thanks for any assistance!