Suggestions for Bad Noises From Motherboard Fan

In the last week or so, the cooling fan for the memory controller on my motherboard has started slowing down, accompanied by a large increase in sound level (it sounds like a grinding noise). The motherboard is an ABIT IS7-E (Pentium 4 Socket 478). I’m assuming the fan is about to fail, although temperatures for the motherboard appear to be stable right now. I’ve checked my power supply and it seems to be working properly. I also blew out all the dust on the fan with compressed air, and applied a drop of light machine oil to the fan, but the problem remains.

However, I’m not sure what part to order. Here are my questions:

  • According to the manual, the fan covers the Intel 865PE Memory Controller Hub (MCH). Is the MCH the same thing as the North Bridge or South Bridge? Newegg has fans rated for the bridges, but doesn’t have any listings for the MCH.
  • The fan looks to be about 40-50mm, and it’s mounted on a cylinder-shaped heatsink. All the fans of the appropriate size on Newegg have rectangular heatsinks. Can I just replace the fan and keep the original heatsink?

I just can’t seem to find a part that looks anything close to the one I’m replacing, which is troublesome. Any guidelines or suggestions would be helpful. If anyone has any ideas for solving the problem without replacing the current heatsink/fan, that would also be appreciated. Thanks in advance.

It’s probably the northbridge – south bridges don’t often get active cooling.

These fans don’t need to move much air, so you can generally shop for three things in particular: noise level, fan life, and aesthetic appeal. Provided you can physically mount the thing, you don’t usually need to worry about it doing a good-enough job.

In general unless you’re overclocking, something that will reassure you about selecting an appropriate fan is to observe that on various motherboards with the same chipset you will find passive northbridge heatsinks (albeit slightly larger) that do the job of maintaining system stability just as well as active ones (in other words, the fans are half marketing to begin with).

If you’re uncertain of fit, you can probably find a replacement fan and heatsink combo designed to fit intel northbridges.

in my experience, you can replace the fan without replacing the heatsink. pull the fan and see if the screw just thread down in between the heatsink fins or whether there is some kind of proprietary mounting bracket. if they thread right into the fins, you can put anything on there as long as the mounting holes aren’t outside the heatsink.

also in my experience, those little fans don’t really make much difference. mine went bad (noisy, like yours), so i replaced it. it went bad again, so i just said fuck it and threw it away. it hasn’t make any difference. disclaimer: this isn’t my main gaming machine, though i’m still pretty tough on it.

Er, if you have a recent-gen vid card and you’re running a recent-gen game, I’d strongly advise against shit-canning your fan and going commando. Unless, you know, you have a hook-up for free motherboards or something.

If you’re not overclocking, throw a heatsink on it and keep an eye on temperatures. If it’s stable, problem solved.

You can replace the mobo for like $50. Rip the noisy fan off, see what happens. If it gets too hot, take the side of your case off until the new mobo comes in the mail. Don’t spend $20 replacing a tiny fan on an old $50 part, doesn’t make sense.

FWIW, my Northbridge fan went noisy on my AI7 recently, so I disabled it: just relying on the heatsink and case fans to keep it cool. No problems so far, but I don’t OC my machine (or even push it very hard) and my basement’s pretty cool, so YMMV.