Black screen of death.. HELP!

HI,

I am getting frequents black screen of deaths.

Very few times, what I see is Black screen while working on After effects or browsing internet or watching movies, today I got 2 black screen while playing multilayer MW3 and even on Batman.

What it does?
The screen goes black and CPU is running. Keyboard lights goes off.
1 in 10 times I see that whole system gets restarted again.

Graphic driver is latest updated.
CPU temp are 30-34 C idle and 45 C while playing games
Mobo temps around 38 C normal, 50 while playing games.
RAM are okay in MemTest.

I recently tested my system with Performance test with all test and it shows result as 2022.4
http://s29.postimg.org/icsp0avav/Untitled.png


What can be the issue of black screens?

I checked my CPU it has black lines.. See images.
I tried to rub it with cloth and it was getting off, is that dust? Will that effect? If yes, then how can I clean it in a better way? Is this CPU is issue?

http://s28.postimg.org/74qwvz9h9/DSC_0003.jpg
http://s28.postimg.org/eainyfikd/DSC_0007.jpg


My system specs:
Mobo: ASUS M4A88T-M
CPU: AMD Phenom II X6 1090T BE
CPU Cooler: CM Hyper 212 EVO
GPU: EVGA GeForce GTX 560 Ti DS Superclocked
PSU: Seasonic Gold X 650W
2 HDD
12gigs RAM

Dump files:
http://1drv.ms/1nL0qVj