Finally got around to digging into the organs of the PS3, I installed a couple of remote voltage sense lines on the fan voltage leads, as well as the temperature sense lead. I put it back together, and closed up the case, turned on, and I read 18 volts at start then it dropped to 12. Loaded FOM and let the blu-ray spin up, and put the voltmeter on monitor capture. After a couple of minutes of game play, I heard the fan kick up a notch in sound level, and saw the voltage climb from 12 to 18 volts. The temperature sense lead is a low-high switch, (at least that's what's happening on my box...) and turns the voltage select from 12 to 18 when the temperature on the heatsink sensors get a bit warm. I tried to borrow a Fluke Hydra monitor and log the temperature data, but, it's in use right now... (Test equipment I used for voltage monitoring was a Fluke Model 189 with event trigger record/playback.) I hope that this ain't overkill, for a question that may only have needed a simpler answer, but, electronics is not only a hobby of mine, but it's also my employment....so...I guess I have the best of both; I get paid for doing a hobby...
Alien