Booting Problem: PC starts to boot then monitors turn off with PC on

[stang3o2]

My pc started freezing today while using it. a few min would pass and it would become usable again. This happened a few times and then just froze. I restarted it and now the pc will begin to restart and will show the boot screen that says press F12 for bios and then the monitor goes into power saving mode.

The pc continues to run, fans and lights are on but the monitors go into power save. I have a wireless keyboard and the receiver has a green light that stays on, however I have a wired gaming mouse and the lights on the mouse do not come on. I've tried swapping usb ports and the mouse lights never come on but the keyboard lights do.

My initial thought was video card or power supply, however the pc is running until I manually turn it off so maybe the power supply is ok?

Any ideas on what to do to fix it?

Thanks

The pc is a windows 7 64bit machine, it's about 5 years old.
Intel i3 sandybridge
2x Sapphire Radeon 6450 gpus running 6 monitors
8 gb ram

 

[stang3o2]

Worth noting, when it froze today, 3 monitors had a crazy looking multiple horizontal line pattern on all of the monitors on 1 card, but the 3 monitors on the other card were still showing my normal wallpaper. The pc was froze and I had to restart it.