bad cpu?

i got a thermalright sk-7 and a sunon 84 cfm fan. i got some as3 for the thermal compound. when i installed it and started my computer it said that system failed memory test. i tried 2 other sticks of ram and tried them in all of my memory slots, i still got the same error. i sent the board back to asus and they gave me a new one. when i got it back and tried it again i still got the same error. i once again tried the different sticks of ram but still with the same result. the only thing left i can think of is the cpu. any thoughts?
i have an asus a7v333, amd 1900+, 512MB pc2700 corsair ram.



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