New build problem! :(

[Crystlemage]

Well here i was finishing a perfect build about 3 months ago, and i started having random shutdown(totally random, no warning nothing).
My build:
Rampage 2 extreme
Intel core i7 920 D0
Patriot ram (6x2gb)
Corsair 750w
XFX ATI Radeon HD 5770 XXX Edition 1024MB GDDR5 PCI-Express Graphics Card
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So far ive rma'ed the motherboard, came back with no problems, tested the ram and power supply, the last thing i have is the cpu, which was running perfectly, normal temps etc, but i think its faulty, i would rma it but i bought this cpu from ebay, and as i dont have proof of purchase so i cant sent it back to intel for warranty, the problem is that im not sure if i should give up and re sell each part or just buy a new cpu and then find out that it is or isnt the problem.

P.s: The thermal paste is fine, their is nothing wrong with the way its setup ive, taken it a part and put it back together si many times i could so it blind folded, the inside is cooler than the weather we are having now

I appreciate the help

 

[Crystlemage]

Default Voltages, i tried not to mess with anything, and the system doesn't stay on long enough for a bench mark :/, actuly when i first turned it on it did stay on long enought, it stayed on about 2 hour, i ran this 3d thing, but cant remember, the only thing i remember that it was a bit laggy , my problem is tht i have no idea what to do its sooo depressing , ive taken it to 2 repair shops both say diff things, ive narrowed it down to cpu, and im not sure if thier is somthing wrong with the vlotages or somehting like that or cpu