Damage to HD 4870, or something else?

[TaskTool]

After my most recent crash (doubt I am just noticing it now) I have started to see like this extremely strange thing going on with my screen. It's like some pixels are in motion, similar to white noise on a tv, like a slightly grainy image. It's only noticable on like bright colors and sharp images on the screen. For some reason I figured maybe screen refresh rate would influence it somehow, and so I upped the refresh rate to 75, and my whole desktop image (default windows 7 wallpaper) was like in motion/grainy, it was ALOT worse.

Is this a result of damage to my graphics card after overheating and crashing? Or could this be the result of my monitor going bad? It's a really really cheap 99 dollar 17 inch.

This thing is driving me crazy, at first I thought maybe my eyes were messed up or was seeing things.. Has anyone had this before?

 

[Slaymate]

It sounds like the video card is trying to die. Is the card still under warranty? If the warranty is out of date I would "carefully" remove the heatsink assembly from the card, clean it and the card itself with compressed air and a clean rag to remove the old thermal paste. Then apply new thermal paste, re-assemble the parts (don't forget to plug the fan in) and see if the problem is fixed.

Newegg.com - Tuniq TX-2 Cooling Thermal Compound

 

[TaskTool]

It sounds like the video card is trying to die. Is the card still under warranty? If the warranty is out of date I would "carefully" remove the heatsink assembly from the card, clean it and the card itself with compressed air and a clean rag to remove the old thermal paste. Then apply new thermal paste, re-assemble the parts (don't forget to plug the fan in) and see if the problem is fixed.

Newegg.com - Tuniq TX-2 Cooling Thermal Compound

Thats the problem. My card was under XFX lifetime warranty until I removed the heatsink and applied new thermal paste. After applying new thermal paste the temperatures went higher than they were before.

Removing the heatsink is a pain in the *** because I need extremely small screwdrivers to be able to do so, and I had to borrow some. Then I have to put the plastic cover back onto the card which is so difficult to do because of the little plastic pieces.

If I sent the card back to XFX would they find out I tampered with it?