2 Dead CPU's

[Styx12345]

Purchased a DIY system from newegg about 4 months ago now and assembled it. Ran fine for about two months, and I decided to add a 2nd video card and 2 more sticks of ram. Ordered/installed that and system ran fine for another month.

One day when playing a game the system crashed on me. Restated it and continued playing thinking it was a programming error (there was just a update on the game). It died one or two more times, and then the system refused to start back up. Video card/case fans turned on, HD spun up, CD tray opens, but no CPU fan movement and no POST beep(s) at all. System powered up using the case switch, but will not power off unless I turn the PSU off. Reset BIOS, tested with 1/no RAM sticks to see if I could get a beep, took a video card out (why not). Decided it was the CPU, and RMA'd it. New one came in the mail (I assume they tested it and confirmed it was dead) and installed it, computer ran fine for about a week, until I played a game again (same one). Computer ran fine the entire time, turned it off to go outside for a couple hours, came back in and I have the same symptoms as before. Won't boot, no CPU fan, no POST beeps, etc...

I assume that the CPU is dead again, but I am wondering if something is frying them under a load. I don't want to go back to the CPU manufacturer again if my MB or PSU is frying the CPU. I know that I can test the PSU voltage, and will do so, but if this problem is only occurring under a load I was thinking that the PSU may test fine unless it's pushed, which I can't do. Also if it is the PSU, should I be replacing the MB as well as the PSU and CPU? Any input would be appreciated.

System Specs
Processor - AMD FD6100WMGUSBX FX-6100 Zambezi 3.3GHz 6 core
MB - GIGABYTE GA-970A-D3
PSU - Cooler Master M700 RS-700-AMBA-D3 700W
RAM - Corsair CMX4GX3M2B2000C9, 4 sticks 8GB total
Video Card - Two GIGABYTE GV-R685OC-1GD, running crossfire
HD - Seagate Barracuda ST31000524AS
CD - LG Black UH12LS28 OEM

 

[smorizio]

to me it sounds like there a bad cap or voltage reg on the mb. if you has a spare power supply i would tell you to connect it and see if the error stops with a new ps. as the system fried two cpu in a weeks time and it happens under load sounds like the power reg in the power supply under load letting in a lot of ac ripple or the mb power cir is not holding a steady 3.3v and frying your cpu. i would use your rma warranty and replace all three parts. let the mb and power supply vendor know that there product has been killing cpu under load. (they will have to use an o-sope and other tools you dont have to watch the voltage on the mb from a known good power supply. if you had a bad hard drive it would burn out the sata ports on your mb or the mb chipset as soon as you turned the drive on and used it. a bad video card would lock up or artifact.. but both the hard drive and video card get most of there power from the plus 12 volt legs of the power supply. the video also gets up to 75v from the pci bus. the other voltage a hard drive uses is 5v for the logic. as bot hthe ps and hard drive are fine that leave the 3.3v leg is question.

 

[DJDeCiBeL]

The CPU uses 12V, not 3.3V, but otherwise, I basically agree with smorizio's assessment. Either the mobo or the PSU isn't regulating the voltage well, it seems.