New pu and gpu, computer boots but shuts down shortly after any help?

GetCracken23

Honorable
Aug 22, 2012
2
0
10,510
ok so ill be as descriptive as possible.
my old rig > Intel Core 2 Quad Q8200 2.33G 1333FSB, 320GB SATA2 HD, 4G DDR2 RAM, Xion 580w PSU, ATI Radeon HD 4350 512MB DDR3, Killer K1 high speed network card, Mobo MSI Intel G31M-L GMA 3100 1333FSB, Windows XP SP3

yes i know very old like early '08. i upgraded the PSU and GPU too a Thermaltake TR2 600w, AMD Radeon R6750 1GB DDR3

when i was taking everything out i cleaned it as well. there was like a pound of dust in it. i took the CPU heat sink off bc it was the dirtiest, and doing so i got a small amount of paste on my finger. i put everything back together it turned on booted, i started to install the new drivers, then black. everything turned off. i tried starting it again but it wouldnt even turn on. So the next morning i try again it turns on this time but for 30sec. the time it stays on varies depending on how long i let it stay off. im no proffessional just a nerd. save me please and thank you.