Just spoke with IBM rep about fan cycling---

[MelissaBF]

He said 9 times out of 10 it is caused by the hard drive protection thing being set too sensitive. Has anyone heard this? tried changing it? Just curious. thanks.

[Conmee]

Melissa,

There isn't APS (hard drive protection/motion sensor) on the T40/T40p models... APS wasn't introduced until T41 series.

I had a couple T40, T40p, and T41 models that all made the cycling fan noise. However, many folks either aren't bothered by it, or more importantly, don't experience the problem at all. Both the short and long fans in the T40/T41 series made the noise, for those that were affected. And in some cases, even changing fans as I did, didn't work for some folks, though it did for me.

If you get a system with Radeon 7500 you will get the short fan. If you get a T40/T41 with Radeon 9000 32MB, you will get the old FireGL long fan, and if you get a T40p with FireGL 9000, you will also get the FireGL version of the old long fan. If you get a T41p with FireGL T2 128MB you will get a more recent long fan, and if you get a T42 with either a Radeon 9600 or FireGL T2 you will get the latest long fan. I've tested/worked with about 6 T42 and T42p models, and none of them have any annoying sounds from the fan. So whether it was the fan, the BIOS, the grounding, whatever, it's fixed, as far as my experience can tell.

*Short Fan (14" MR7500/non-FireGL) FRU# 91P8393
Short Fan (15" MR7500/MR9000/non-FireGL) FRU# 13R2919
*Long Fan (MR9000/FireGL 9000 64MB) FRU# 13N5442
Long Fan (T41p FireGL T2 128MB) FRU# 13N5347
Long Fan (T42/T42p MR9600 and FireGL T2) FRU# 13R2657 **This fan replaces previous FRU# 13N5347 Long Fans according to the latest hardware Maintenance Manual**

If you know the part number of the ThinkPad you're interested in, download the HMM here... and look under Parts List/Overall and it will list all the models and which fan goes in which model.

http://www-307.ibm.com/pc/support/site. ... MIGR-46464

The fans with asterisks are the potentially noisy fans.

Hope this helps.

Daniel.

[krosenstein]

Am I correct in assuming that these fans aren't interchangable? I have a 2373-9FU that has the noisy long fan.

Is it possible to swap that for the quiet long fan?

If so, is it user swappable?

[Conmee]

I've swapped out three different fans, one short, two long. This will 'void' your warranty. But if you're careful and don't leave fingerprints, and replace the original fan if you need service, who will be the wiser? lol... Technically speaking it isn't a user replaceable part, but it's easy enough to do, just follow the Hardware Maintenance Manual.

Daniel.

[krosenstein]

I take it then that they are interchangable. What is short and long on them; in other words, how are they different (other than sound level)?

[Conmee]

I take it then that they are interchangable. What is short and long on them; in other words, how are they different (other than sound level)?

One is short, one is long... lol

That's it. The long fan is about 1.5" longer and extends to cover the entire ATI GPU, whereas the short fan only covers the CPU. In addition, the long fan replacements I ordered also had some additional foam and aluminum taping around the edges near the exhaust vents on the left side of the Thinkpad where the fan touches the casing. That's it. The power cable, screw locations, metal, color, are all identical. That's the long and short of it.

Daniel.

[spirifer]

I changed my fan (short fan on T41 with ait 7500) for the 13R2657, and i have always the problem of fan