To fix PS3's from YLoD you need to reflow or reball, but to keep it gone you should replace he thermal compound under both the CPU & GPU heat spreaders as well as on the heatsinks.
Problem is the thermal compound dries up, so it gets too hot, solder joints soften then go cold or crack, so a reflow or reball is needed to fix that, then replacing the thermal compound with Arctic Silver 5 will keep it from happening again.
Replacing the thermal paste under the heat spreaders is VERY important, replacing just the stuff on the heatsinks is virtually useless if the stuff under the heat spreaders has dried up and cant transfer heat to the heatsink in the first place. Fan mod should not be needed.
This post has been edited by herman69: Sep 2 2011, 12:15 PM