Installed Graphics card and psu problem

Hello, I put in a thermaltake tr2 430w psu in my computer as well as a Radeon r6670 graphics card.
When I try and power it up it appears to be running fine no beeps all fans running on cpu psu fan,but my monitor gets nothing. just stays in standby mode like i never hooked it up. I've tried the same monitor on another pc and worked fine.

Additionally i put my old psu and crappy graphics card back in and everything boots up fine now. Do you think its a doa psu or card or did I miss a few steps. any help will be much appreciated it