No Signal from DP on graphics card

[slamgamer8]

I have a Radeon rx 480 4gb graphics card which I decided to try and install an aftermarket GPU cooler onto. I purchased the arctic accelero twin turbo 3, followed all the install instructions and even watched a few YouTube install videos. After finally getting the cooler onto the card, I put it back in my pc and I get no feed from any of the display ports or hdmi ports to my monitor. I actually found a guy on Craigslist who installed the same cooler on his rx 480 and had the same problem. I would rather not have to pay to get the card fixed and don't want to throw it away either. Any suggestions on what I can do to get the DP working again??
Thanks

 

[hang-the-9]

Chances are you broke something when you were changing the cooler. Since you did nothing else to the card, that is the only possible reason the ports do not work.

 

[DRagor]

I would consider possibility that new heatsink touches something that it should not, and creates short. Are the other ports working?

 

[slamgamer8]

DRagor, I think you're right about the heatsink causing a short. I heard of that being a problem with this cooler.
There are 3 display ports and 1 HDMI and none of them give any output to my monitor.
Do you know of any solutions I can try at home? Do you think I will have to ship the graphics card off to get it repaired?

 

[DRagor]

You would need to find where the heat sink touches some wires/components that it should not, and put some kind of isolation between the component and heat sink. Obviously that would require to remove it first. At that point it would be good to check if the card still works at all (might require to install old heatsink temporary), because if it does not, then you probably broke something, as hang-the-9 mentioned.

 

[slamgamer8]

So I reinstalled the stock heat sink and gpu cooler. When I start the pc, the fan fires up for a few seconds then slowly stop rotating. Still not getting any output to my monitor either. This makes me think that the heat sink from the aftermarket cooler has done some permanent damage to the card.
Is there any way to test the graphics card or the GPU itself?