Update on what Darko said above: Fan not working, CPU overheating, throttling, turning down unexpectedly. There are knocking, high-pitch buzz or similar sounds from fan, faster with temperature rise (this is actually the PWM sound that is trying to spin fan faster, but it can't spin at all). The problem is not in fan itself, fan is OK. The power to fan is delivered through a small resistor (UPD: as elektrosha discovered, it is a permanently failed resettable fuse) at the mainboard. Overtime it degrades and in my case was 40 Ohm, which is way too much voltage drop to start a 0.5A fan. So the steps are (on your risk of course): (1) You disassemble the laptop (powered off, unplugged). There are 2 types of screws, long and short, mark by any sort of scotch tape the places where were the short ones. Some small latches, open the screen and keyboard kicks off. (2) Disconnect the battery from the motherboard. There is a obvious connector from battery to MB in the center. (3) Locate the %#*@ 0603-size resistor 1cm...