Strange CPU fan behavior

[ZacharyB]

Hi everyone,

The fan resting on top of my CPUs heat sink won't spin up all the way. It makes a few rotations and then looks like power is cut, then makes another few rotations, stops... it does this over and over again. I don't know how long it's been doing this, and I don't use my computer heavily--just drawing with a really simple graphics program and a few other simple programs--so the computer's never warned me of overheating, I think.

I went into my BIOS and checked the computer temp... This motherboard has something called Smart Fan, where the fan only comes on after a certain level of heat. I disabled that, but the fan is still doing its little dance. The temp of the CPU read something like 48 degrees celcius, which was beyond what the Smart Fan setting was at, but below the other two optional settings, which were 60 and 70 degrees. To summarize, the Smart Fan doesn't work, but I can read my CPU's temp, so the thermal sensor is working?

I don't know what's going on, this's never happened to me before.

I don't know the motherboard precisely; it's some nVidia motherboard. It's red and at least five years old. I'm using Windows 98 SE on this machine. Everything else on the machine seems good; there's another fan blowing into the case that's hooked directly up to power, and that seems alright. Any advice on a course of action?

[nZero]

The fan resting on top of my CPUs heat sink won't spin up all the way. It makes a few rotations and then looks like power is cut, then makes another few rotations, stops... it does this over and over again.

I don't know the motherboard precisely; it's some nVidia motherboard. It's red and at least five years old. I'm using Windows 98 SE on this machine.

Any advice on a course of action?

1) Sounds like the bearing gave out on the fan. If it's a fan with a standard size (e.g. 60mm, 80mm) and bolt pattern you can get a replacement from just about anyplace that sells computer parts online. You shouldn't even need to replace the heatsink, although you might want to blow the dust out of it with a can of compressed air or something while the fan is removed.

2) Consider a new computer. Not a lot of new software supports Win98, and past the 5 year mark you're going to be looking at other maintenance items as things such as other fan bearings, power supply capacitors, even hard drives (back up your data!) start to reach the end of their useful lives. Capable notebooks or complete desktops running Windows 7 64-bit should be starting around $500.