I had a dead 12" white g4 powerbook. This happened to the cpu.
I figured I had nothing to lose, so I took out the mother board, wrapped all of it bu the cpu with aluminum foil. I put a tea light on the chip (it was about the same size) I fired it up figuring it would be a prayer to the computer gods, or part of a wake ceremony.
Once everything cooled off the laptop worked, still does.
I wonder if a little heated press could be made to heat up and re-seat the chip without letting it slide at all. Sounds like an aftermarket tool business if anyone wants to make it.