I hava a BC 80gb Motorstorm PS3 and the last couple of months my PS3 has YLOD 3 times now. I fixed by myself applying thermal paste and reflowing it with the heat gun and all. The first time I guess it was time, beacuse the PS3 is old (from January 2008) but the second time, after opening it I realised that the plate covering the RSX wasn't in full contact with the heat sink so that was the problem, but now I dont have any clue.
There is something I can do to fix in a more permanent way? Or anyone have a tip?
The weird thing is that the first time it YLOD while gaming, but the other 2 it YLOD when it was shuted down, I was playing then shutdown and hours later when I turned it on it had the yellow light.
I don't know but I think that keeping the PS3 vertical doesnt help to it.
I would imagine that the issue is similar to what happens with 360's (which I have a ton of experience repairing). The PCB under the CPU/GPU probably warps slightly from heat buildup and causes a disconnect with the IC. The heat gun method works, although it is not very precise. It is probably not worth it to do it yourself, but if you could locate someone with a proper hotplate reflow station you might be able to fix it more permanently. Other than that, I am going to have to refer you to someone with more experience with repairs on the PS3.