Finally solved the 'my 40GB PS3 Phat sounds like a wailing banshee' problem!
I once again stripped the PS3 down to the mobo then applied Arctic Silver 5 to the CPU and GPU, this time using the 'line method' of application. End result? A near silent PS3!Last time I tried fixing this issue I put a paper thin coat of AS5 on the CPU and GPU but I later found out this method is useless as the chips don't make contact with the heatsink. Playing games/watching BD's now without the sound of a hairdryer in the background is pure bliss...Now to install a 500GB HDD and buy Play-TV!