RE: Precision M6500 Heat & Shutdown Problem
The video card assembly is visible in the background of this photo. With the CPU heatsink removed, just a few more screws and one more electrical connector are involved with removing it as well. Removing the fan from the assembly (3 screws) allows for thorough cleaning of the video card assembly heatsink. (The M6500 may have different video cards, so perhaps some are more difficult.) My CPU heatsink was just as dirty as the one in your picture, and the video card assembly heatsink was half as bad.
Thank you for your post - I cannot believe how hot and slow my computer had become before I recognized the problem, with your help!