A while back I posted a question, but no-one replied :(. I did a bunch of research and I'm fairly good at fixing retro consoles - but the PS3 is another level of complexity.

Anyhow I did solve it - and now the machine is quiet as a mouse while playing movies or games. While running you can feel a flow of constant hot air coming out the vents (which is good - it means the heatsinks are doing their thing).

Before I posted the question I had redone the heatsink compound paste - that helped revive the machine from immediately shutting down to at least starting up. I could play games, but the fan was noticeably noisy. While playing bluray movies the fan ran at top speed - you could barely hear the movie soundtrack. On PC's and servers - super fast fan speed often means the chips are not being cooled properly (the system controller is like - it's really hot down here - speed the fan up a bit?).

A lot of repair guides on the net actually don't mention you need to replace the heatsink compound between the cpu/gpu chip die as well. I cut those off with a heat gun (to soften the glue) and a custom knife I made out of a painting knife - the heatsink compound underneath the heatsink spreader for both the gpu and cpu was dry as a bone. I replaced it with some arctic silver 4 (AS-4).

This youtube video goes in excruciating detail into the process I did myself.

Not kidding btw - this is the quietest this machine has ever been ;). I have left it overnight playing a bluray disk on loop and it's fine. I've been using the machine on and off for a week or so now and no problems.

In researching this btw I did find there's basically two levels of PS3 grief:

Overheat and shutdown automatically (which was the state of my machine)

YLOD and shutdown - this latter is caused by some chip or component failing to initialize properly - the most common cause is bad ball grid array (BGA) connection on the GPU. You can use shims to put more pressure on the array (I have to wonder if this will warp the pcb), but the ultimate fix is to redo the solder balls with leaded solder using a rather expensive rework reballing station.

I'm pretty sure if anyone wants their PS3 to be around for another 10-20 years you'll eventually have to deal with these two problems (worth mentioning - its not a retro console yet, but in another 5-10 it will be).

Anyhow - thought I'd share ;).