New GPU not working

[invalidd]

I'm new to PC, and I planned mainly on using one to play games so I of course decided to buy a decent GPU. I bought a Radeon R9 280 off newegg. It just arrived today and not knowing much about installing it, i went very straightforward with it. I removed my current GPU, an Nvidia GeForce 720, and placed in the Radeon card. I booted up my pc using an hdmi connection, which took a few tries to work for some reason, and I downloaded the drivers. First thing I noticed was that the screen had a black border around it and wasn't filling my entire monitor and I also found out I should have uninstalled my previous drivers. I did just that and restarted my pc to my surprise didn't actually restart but remained on a black screen. Now it won't start up, I've tried reinstalling drivers and all that, but no video output comes up. My previous card works just fine yet and onboard graphics as well. Most likely not my 650W PSU's fault. Do I have to RMA or can I salvage this card?

 

[learningbitbybit]

Do you have another GPU that you can test it out with?

 

[invalidd]

Do you have another GPU that you can test it out with?

My Nvidia GeForce 720 still works just fine.

 

[learningbitbybit]

Okay then try going to the amd catalyst control center and try adjusting the settings or scaling, however you would like to call it.