So I was doing some light web browsing in an AC'd room and noticed I couldn't hear the laptop anymore. Usually it makes a very faint noise in a quiet room and when it stopped happening I noticed it. Anyway the CPU fan seemed to be off, no noise or air was coming from it at all. I loaded up HWMonitor and sure enough the CPU fan speed was 0. The GPU fan always reads 0 as well but the CPU usually reports 2200rpm+.

I watched the temps and they actually seemed fine. I started loading web pages and the temps slowly increased until the GPU hit 45c and the GPU fan switched on (as per normal) and cooled it back down. But the CPU fan stayed off until a few seconds after I restarted the laptop.

Has anybody had this happen before? It's bizarre as hell I didn't think the CPU fan ever switched off no matter what. I was tempted to load up a game to see if it switched on at higher temperatures but decided not to.

I can't seem to replicate it either, I've left it idling in the same room and it doesn't switch off which is what I assume to be normal. I guess the cool part is that the heatsinks are not too bad at passive cooling. If I'd have stopped using Firefox it could probably stay < 40c for quite a while, and the GPU fan would kick in anyway eventually.