Black Screen after Overclocking

I recently tried overclocking the GPU for my Radeon HD 5770. I then tried to use the 3dmark benchmark test. During the test the screen went black and I had to restart the computer. After it restarted the clocks reset back to default, and everything seemed to be working fine. However, when I try to play video games now I get the same black screen and have to restart. Everything else works fine. Anyone know what is going on?

 

There are couple of things I would try,first uninstall then reinstall the latest WHQL driver do a clean install removing all your profile and custom settings,download and install the latest DirectX,remove the card,clean out the fan and reseat.

Reset your motherboard bios,with the power disconnected remove the coin shaped battery for 20secs then replace

On the face of it,it does sound like you've KO'd the card but that depends on the type of blackscreen,if you don't see anything on the screen it could very well be a setting problem,if you can game for a short time before it locks up I would lean more toward the card being damaged a little more info on when you encounter the black screen would be helpful.

If you would like help figuring it out supply a little more information,your computers specs if you don't know download and run speccy and add them as an attachment, operating system , the make and model of your power supply and the information written on the side,the software your using to overclock and monitor your temperatures and stability,the overclock you were going for including the voltage your were using and the temperatures you were running at.