DVI no signal (GPU problem?)

[BigMach]

I just recently built a PC with these specs:
CPU: AMD Athlon X4 860K
MB: Gigabyte GA-F2A88X-D3H
GPU: PowerColor R9 270 TurboDuo
RAM: 2x4GB Corsair Vengeance DDR3-1600
Storage: Crucial BX200 480GB SSD
PSU: Corsair CS450M
OS: Zorin OS 9 Core 64-bit (Ubuntu 14.04 LTS)

This PC was working fine, until I came back to it after putting it in "Suspend" and the screen said "DVI No Signal". The Monitor works fine (I tested it with an HDMI cable), but I think that my GPU may be at fault. All of the fans are spinning and the MB is getting power. I did overclock it and push the voltage from the stock 1.188 V to 1.2 V (maybe 1.205?). I think that the increase in voltage may have caused the problem, but I cannot be sure. I do not have an APU, therefore, I can't use the computer. Any ideas on how to identify the problem?

 

[renz496]

So all output from your 270 only result in black screen?

 

[BigMach]

So all output from your 270 only result in black screen?

I actually found out that it was an OS related problem. My PC is working fine. All I did was wait a few days until I decided to give it another go and I put the 270 back in w/ DVI-D connection and it worked.