I've just completed a GPU reflow on a T42p and noticed that the long fan covering the GPU has some hardened black material unlike the white thermal grease used on the CPU. Can anyone identify it or suggest a suitable replacement so that it can be reassembled?

See the threads T42p fan long m10 installation : pink sheet or not...? and T42 Fan replacement and/or Thermal Paste/Themal Pad and/or Questions on Removing the Fan Unit from a T42.

Johan

Thanks for all the reading tips. I cleaned off all the black gunk from the GPU and under the heat sink. When I dry fit the fan back onto the MB, it fits snugly over the GPU. There's a copper shim that fills the gap so it doesn't look like there is any room for a 2mm thermal pad, or even a 1mm. Is there a special compound like the original or can I just use the white thermal grease? The top of the GPU is flat and smooth.