System is inconsistent when booting and shuts down randomly

dannyboy111222

Honorable
Feb 1, 2014
6
0
10,510
Pretty much whats in the title. It failed to boot multiple times however was still on, during this time there was no output, while in this state it couldn't be switched off from the power button but only from actually switching the PSU off. CPU and GPU fans were still spinning.
At last it finally booted after being left on for about 7 minutes. Before this I had experienced some random crashes for about 2 weeks with no apparent cause. Any help appreciated. My specs are: and fx 6300, EVGA 650ti boost, asus M5A78L‑M, an xfx 550w PSU, I recently got a 750evo after my HDD failed. There's also quite a bit of dust around the CPU, could this be a problem?

UPDATE: The PSU seems to be working fine, I plugged it in to another computer which ran perfectly