P7811 Screen Turning Off

About 2 years ago I bought a P-7811 FX from best buy, and recently the screen started to randomly turn off when I'm playing games. The games where this issue happen are all relatively new and graphics intensive (MW2, Just Cause 2, etc.) which led me to believe it's a temperature problem.

My GPU idles at around 45 degrees C and peaks at around 90 C under gaming. I know it's a bit high, but it was always like this for the last 2 years and nothing like this happened. I have a laptop cooler and clean the GPU vent relatively often. I also tried a few new drivers from laptopvideo2go, but the issue actually was worse with the newest drivers (258.XX).

When it happens, the screen turns OFF (not just a black screen), the sound loops and crashes, and the only way to fix it is by rebooting the computer.

Any of you have the same problem? I'd prefer not to take apart my computer to get to the GPU, I'm not sure if I could put it back together again...

Edit: I did some searching and tried the Rivatuner force performance method to force the clock speed at 400/300/800 all the time, while it worked, it also made the 3DMark06 score decrease by 3000, as well significantly reduced FPS in games.

 

Sound loops and crashes, pardon the pun, sounds like the 2D to 3D timing issue with the ram. There is a modded bios but I believe others have found ways through, stretching the memory here, riva tuner to combat this...........

I'm not a gamer so not too much help here but search the threads.............

 

Hmm, I tried the rivatuner method, but it's basically a huge underclock...
Sure it works, but it also means reduced performance... thanks for your help though.

Is there a way to force it at the highest clock level (which Rivatuner doesn't seem to support), but only when a game is running? Thanks