I've got a weird one for you guys. I'm wondering if my problem is with my motherboard or my RAM, or both.
I have 4 sticks of DDR3 RAM. Two 4GB, and two 8GB. All 4 used to work until my PC crashed one day and kept performing repeated restarts immediately after booting. No boot screen or anything, just rolling restarts with black screen (no signal on monitor).
I mixed and matched each stick on different slots until it booted. It started booting with 4GB on slot 1, and 4GB on slot 3 (dual channel). Adding either of the 8GB sticks to this mix either causes the rolling restarts again, or a simple failure to POST (PC turns on but no signal on monitor).
Here's the kicker: if I change the positions of the working sticks to other slots, it'll either work, or not work. It seems random. Even putting the sticks back into slots 1 and 3 will sometimes cause POST failure.
The 8GB sticks don't seem to work in any configuration.
My gut tells me it's a motherboard issue but I'm not sure. I guess it could be the CPU, too.