T42 Fan error - fan or motherboard?

[dr_st]

My (currently sister's) T42 2373-F7G recently started giving out the "Fan error".

Removed the keyboard, powered-on. The fan really doesn't spin. It is not dirty. Gave it a woof with compressed air, still doesn't spin.

The fan is "Fan assembly (long) M10", FRU 13R2657.

Based on the collective experience of the forum, I am trying to estimate:

* What are the chances that the problem is the fan?
* What are the chances that the problem is the system board?
* Any other possible causes for this failure?

Since the laptop is out of warranty, a board replacement is pretty much out of question (not worth it), but the fan I can probably replace.

[Harryc]

There is mention of an F4 fuse in this thread...on a T40 though. FWIW.
http://forum.thinkpads.com/viewtopic.php?p=490765

[ajkula66]

I'd say 70% for the fan and 30% for the planar.

Try locating and replacing the fan, if there's an issue with price and/or availability, drop me a PM.

Good luck.

[craigmontHunter]

I have heard that people have tested what it is by blowing gently on the fan when they turn on the system, and seeing if that solves the problem - that would make it a fan problem since the system can detect the fan, but if it is the planer and a fuse, I don't think that there would be any signal.

[sktn77a]

If the fan connector is disconnected or the fan motor is open circuit, you'll get the fan error no matter what. Do you have access to another T4x that you can temporarily swap fans (doesn't need to be the long fan for this test).

[dr_st]

If the fan connector is disconnected or the fan motor is open circuit, you'll get the fan error no matter what. Do you have access to another T4x that you can temporarily swap fans (doesn't need to be the long fan for this test).

Not at the moment, although I might soon. I might also just be able to locate a spare fan somewhere.

[mr.motoring]

The fan is dead. Long fans die quite often since they have to cool the GPU as well as the relatively hotter higher-frequency Pentium Ms, thereby making them run more.

Short ones, on the other hand, almost never wear out. If you don't have any working long fans, you can use the fan from a short heatsink from any T40-T42 (after swapping the housings).

This is after testing with a short fan first like sktn77a said.

[dr_st]

BTW - a question - is the fan connector the same between the T4x and other models, e.g. T60/T61? It may be easier for me to test with a fan from a T6x, if I can just connect it and see if it spins or not. But the connector must be 100% the same for something like this to work.

[richk]

Even if it fit, I would be afraid to try it unless someone can say that they know it works. I have no idea if the resistance of the fan motors are the same. I would be afraid to wreck the motherboard. If the t60 fan runs at lower voltage, it might have a lower resistance motor and draw too much power.

[dr_st]

Yeah, I wouldn't do that. I decided that I am complicating things too much here. IBM gave me a very good price on 41W5204 (which replaces 13R2657), so I'll just go ahead and get it. If I'm SOL and the problem is the mobo, then the money spent on an extra fan (which can always come handy), will be the least of my concerns.

[dr_st]

Just to have some closure.

The fan I bought from IBM arrived two days ago. I tested it by connecting it to the board, and well, it worked. So it really was the fan.

Today I finally got around to actually replacing the fan in the chassis, and reassembling the laptop together. Everything works now. The old heatsink looked in pretty bad shape. The soft padding on the edges was partially torn and melted, and some of it was stuck to the GPU, which I had to clean.