My very important laptop from 2001 is randomly turning off. I remove the heatsink, and the cpu (mobile Athlon XP 4) is shiny, and under the heatsink is this hard grey stuff. I cleaned the cpu and the bottom of the heatsink with alcohol. The grey substance (presumably thermal paste) didn't come off, so I don't know if this actually thermal paste or some form of thermal conductivity. So I want to buy some thermal grease, but I don't know if my laptop need it. I'll take a picture on request.