Desktop Fans Speed
First time on this forum and I'm looking for an explanation for the behaviour of my desktop fans (CPU, case, and PSU fans). The problem that SOMETIMES and after my child played a game on the desktop, the fans remain at higher than usual speed (22% to 44% as reported by SpeedFan) even though the CPU is mainly at idle and the CPU temperature is lower than 40 C. The fans would remain at that speed until the desktop is restarted or put on standby.
I have done the following so far:
1. Fresh install of XP Pro plus all required updates although I do not believe this is a software problem. I just wanted to eliminate the s/w part.
2. Removed and cleaned the CPU fan, removed and cleaned the thermal grease and then applied a uniform thin layer of RS Heat Sink Compound. This actually improved the overall operation of the desktop where it's quiet most of the time.
3. The case as well as its fan along with the PSU fan have always been clean. As a matter of fact, the case fan has been replaced recently since it was making unusal noise at certain speed.
Overall, the desktop is performing well although I do not use any heavy applications or games. However, under certain conditions, those fans would get stuck at a certain speed and the CPU no longer controls them while it's idling and, therefore, it should drive the speed of the fans to minimum. As I said, the CPU with 96-98% idle and no apps running at low temperature of 40 C or below.
What could cause those fans to remain at that higher speed? Could it be a faulty CPU fan that gets stuck and it drives the other fans? I'm running out of ideas.
Your feedback would be appreciated. Thank you in advance.
Processor Intel Pentium 4 2000 MHz
CPU Clock 1994.2 MHz (20.0 x 99.7 MHz QDR)
Chipset 82845MP Brookdale Host-Hub Interface Bridge (B0-step)
Mobo Compaq Computer Corporation
Graphics nVidia FX 5200