There are 3 elements to fan control. The thermal sensor inside the CPU, which you can disregard since this happens cold. The fan and its connections--if the control signal does not reach the fan it defaults to full speed. The chipset, which at startup loads a control constant from BIOS, but of course the chipset must be running to do this and it sounds like yours isn't.
Your advisors were on the right track about power, and the power supply is cheaper to try than the motherboard. But half the power regulation is on the motherboard and it looks like that's where the problem is. At this time, the power light should be yellow and the diagnostic lights off. If you have those conditions, motherboard is most likely. Just to be sure it's not a cheaper accessory, unplug all plugin cards and USB and if the condition does not change you're back to motherboard.
x_lab rat
2K Posts
0
August 14th, 2008 14:00
There are 3 elements to fan control. The thermal sensor inside the CPU, which you can disregard since this happens cold. The fan and its connections--if the control signal does not reach the fan it defaults to full speed. The chipset, which at startup loads a control constant from BIOS, but of course the chipset must be running to do this and it sounds like yours isn't.
Your advisors were on the right track about power, and the power supply is cheaper to try than the motherboard. But half the power regulation is on the motherboard and it looks like that's where the problem is. At this time, the power light should be yellow and the diagnostic lights off. If you have those conditions, motherboard is most likely. Just to be sure it's not a cheaper accessory, unplug all plugin cards and USB and if the condition does not change you're back to motherboard.