Thanks to this thread, I was inspired to see if I could solve my (bought day 1) PS4 Pro fan problems.
Fans would spin up very loud, and I had to wear a headphones to enjoy games. I don't like wearing headphones.
I have taken apart the PS4 Pro before, and cleaned out the minimal dust that was present, and it made very little difference.
I had some Artic Silver 5 paste lying around, so I thought I would apply that. I notice the paste that Sony applies was a large amount, applied down the center, and large globs hanging over two sides. Looked like toothpaste, which is weird.
I applied Artic Silver 5 all over the chip surface, and just a moderate amount.
There was also some dust buildup on one side the heatsink, which I cleaned out.
I did this in early June, and it has made a marked difference.
Now I can play Battlefront II co-op and enjoy it with out wearing a headset. I can still hear the fans, but they are not bothersome, and the game sound largely drowns it out, where before it did not.
STRESS TEST: GOD OF WAR: I was amazed the fans did not kick into overdrive, which sounds like a jet taking off, and the game was enjoyable to play without headphones!
Very happy, and pleasantly surprised with the outcome, cause my expectations where not that high going in.
Strongly recommend anyone with high fan noise problems to replace the thermal paste, as I believe Sony's automated application in the factory is poorly applied, and probably very cheap quality.
I did not apply new thermal pads to the memory/VRMS's as there are thermal pads there, and I assume they are sufficient. Might next time consider replacing them. They are very small, but not sure if the size of the thermal pad makes much of a difference.
Thanks again for inspiring to do something about it.