HP p7 1254 troubleshoot

[zireko]

Ok I have an hp p7 1254 it has been great for about 2 to 3 weeks but I'm running into a problem. Sometimes the display goes out and says no signal but I've checked all the lines checked the video card and I also checked the sleep mode which I have all power options turned off so that it will not go to sleep. How I fix the problem is by turning the computer completely off from holding the button a few sec. and then everything works fine for a little while. Sometimes the power button turns from blue to orange when this has happened other times it has just stayed blue. Can anyone help me on troubleshooting this plz?

The computer has

amd a6 processor
8 gigs ram
1 tb hard drive

I also replaced the power supply and put a new video card in

Thermaltake 600w
Nvidia GTX 550ti

Also I'm updating the video card drivers now and i've updated the display drivers

 

[haterade]

My old pc was doing the same thing, turned out my GPU had died
I have a HP p7 1157 same specs and am also purchasing a 600w psu and GTX 550 Ti, hope I don't run into the same problem. I'm curious if anyone knows what the deal is.