If it’s a reflow, your PS3 is running on borrowed time. A reflow heats up the chip enough that parts of it expand enough to make the GPU work again temporarily (the solder bumps on the bottom of the silicon attaching it to the interposer line up their cracks again), but eventually you’ll be back to square one. The real fix is to replace the 90nm GPU with a later 65 or 45nm variant that has the fixed design (search up “PS3 frankenstein mod” for more). There is thermal paste both under and above the IHS - the one under for taking the heat from the silicon up to the IHS, then the top layer for taking it to the heatsink. Here’s an image of a delidded RSX and Cell to show (apologies for the quality, was the best one I could easily find). Image

PS3s did cook themselves, but not to the extent of the 360.

It is funny to see how there are probably so many misdiagnosed 360s out there with bad power supplies that have been subjected to being bolt modded (shudder) or something. It doesn’t help that the three red lights just mean “general hardware fault” without doing the button combination to get further information. I guess at least more helpful than the PS3, whose diagnostics were only made available recently due to a key being cracked.