the problem with 60GB fats is twofold:
1) They default fan profile lets it get to like 82C before it really ramps up the fan, then drops it to low again once it hits 78c.
This means the PCB is basically being slow cooked, and it's under some strain from how the heat sink is mounted on it, so it just kind of warps.
2) Sony were retards and just used basic white lithium paste on everything. This isn't as big a problem for the most part, as you can replace it yourself.
The big problem is that they also used this shit-tier paste on the die surface of the RSX and Cell under the heat spreader.
To fix this, you need to remove the heat spreader from the RSX and Cell. The RSX is fairly easy, and pops off with little effort in "most" cases.
Removing the heat spreader from the cell requires one to cut into a 0.5mm gap filled with a very hard epoxy, and can easily damage the Cell. You just have to pray they applied a sufficient amount of paste, or risk de-lidding it yourself.