HD 7970 no monitor signal

pantman_

Prominent
Jul 5, 2017
22
0
510
I have a prebuilt computer and wanted to upgrade. I have a 550W psu, and I bought a used Sapphire Radeon HD 7970 Vapor X 3gb GHZ edition. I put it into my pc, started it, heard the windows noise, the card lights up and fans spin, but the monitor is not getting any signal, though it is definitely plugged into the wall and the PC. It just says DVI: No Signal when I try to get it to work. I only have one 8-pin to Molex cable, though there are to connectors, as the box was missing the other. Is it because of this or another reason?
 

xupitera834

Honorable
May 1, 2017
48
0
10,540
try to pull out the ram and put it again in the same slots then do the same with gpu and see if its' work or try a new psu 600 if anything of this dosent work try to test the gpu in other pc