I purchased a MSI GTX 670 Power Edition back in January. After a month and a half of gaming on it (mostly playing Boarderlands 2), my PC started to instantly shut off, like if you were to pull the power cord out of the wall. About 6-7 seconds later, without touching it, it would turn it self back on. I RMA'd the card to MSI. My second card did the same thing. I RMA'd it as well. I am currently on my 3rd 670. A MSI CSA took an interest in my case, making sure this card was actually tested and not just replaced, when I RMA'd for the third time. He reported to me saying they tested the card for hours and could find nothing wrong.
My previous card was a MSI HD 6870 which ran flawlessly in my PC. If I replace the 670 with my old 6870, my PC no longer has any issues and runs perfectly.
I am at a loss on how to fix this problem. BIOS and drivers are all up to date and driver sweeper removed all AMD software from the 6870. My MoBo is a MSI P67A-GD65 and my PSU is a Corsair HX750.
I have been told that since the 670 is working properly (I use afterburner and GPU-Z to monitor temps, and it never goes above 70C) that the issues has to be my MoBo or PSU. But, this is where I get lost. If I replace the 670 with the 6870, my PC has no issues, so how can it be a MB or PSU issues?
Final Note: The shut offs only happen while I'm gaming, which is the main use of my PC. And it randomly happens. I could be gaming for an hour with no problems or I could be gaming for 5 minutes and experience a shut down. And it crashes in games that aren't too demanding, such as SimCity, DOTA 2, and Star Craft 2.
Really looking forward to hearing what some of you have to say and thank you to all who took the time to read this!
Rig: I5-2500K, 8GB Ram, Win 7 64-Bit. Nothing is OC'd.