Ok...so I have had this issue for around a year now with still no fix...my build is a
Asus P8Z68-V/GEN3 LGA 1155 motherboard
8 gigs of g.skill ddr3 1600 ripjaws
crossfire power color 6870 video cards
samsung spinpoint F3 1tb hard drive
i5 2500k (stock) Hyper 212+ cpu cooler
Lite-On 24x dvd rom
CoolerMaster Scout case
pc power & cooling 750w PSU.
Windows 7 home x64
The Asus motherboard replaced a previous Asrock extreme3 gen3 motherboard because I thought that was the issue, It was not however. (asrock board is now in another rig running smoothly). The pc power and cooling 750w PSU replaced a 650w corsair power supply because I thought that was the issue, however it was not. ( corsair is running smoothly in another rig).
Problem: It does not matter what activity I am doing on the computer i.e. Browsing the internet, playing a game, sitting at desktop, watching youtube or a movie...the computer randomly powers off and starts back up or my mouse and keyboard freeze and I have to hard restart. It is so sporadic though, so I do not know how to pinpoint the issue. It can happen anyday...and at one point i went a whole month with no issues and then i lost power again, however it just happend about 5 minutes before i wrote this. It may happen several times a day or not at all for a week or two. I remailed both 6870 video cards 1 at a time...powercolor sent me a new 6870 and so I remailed the other the next day, I had no issues for a month with the new 6870...the 2nd card came back and they accidently sent me a 7850...so i uninstalled drivers and tried the 7850...had the same power issues again...swapped back to the 6870 and had no issues, however I am now having the issues again with this 6870...so video cards are ruled out as I have tried 4 different cards in total now.
Power supply, Motherboard, Video cards...are not the issue....what could it be? Defective CPU? RAM? HardDrive? or Optical Drive?...nothing is grounding out as I have reseated everything and such several times...nothing is overheating as all temps appear perfect...RAM has been tested heavily with memtest86 and checks out good, prime95 ran for 24 hours no issues, intelburn test ran for 8 or 9 hours no issues...this *** is driving me insane, please someone give me some suggestions on what to try next to solve this CURSE.