12" G4 Powerbook fan replacement? Or logic board?

My girlfriend has a 12" G4 Powerbook that she claimed was getting really hot. I noticed it was as well, so I installed iStat Pro and saw that the fan was spinning at 0 RPM. So obviously something is wrong.

I read a few posts on people having problems with the logic board, which would also cause the fan not to work. However, the computer runs fine, the fan just doesn't turn on when it gets hot. I haven't (and don't plan to) let it get so hot that it would shut itself off or burst in to flame or whatever happens.

I understand it's out of Applecare, but I would prefer to fix it myself on the cheap. I'm perfectly capable and willing to replace the fan, but before I crack it open I would like to know if there is a simple way to see if my problem is simply a dead $30 fan, or a $500 logic board.

Anyone have any advice?

Anyone?

FireArse said:

If you can try get hold of the service diagnostic disks - it'll warn you if the fan doesn't reach the required speeds. I think you might be able to take it to an Apple Genius Bar, if you specify exactly what you want, they could do it there. 5 min job.

A new MLB is far more costly than a heatsink + fan!

F

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Well I know the fan isn't spinning. That's been proven by iStat Pro and the fact that the fan doesn't turn on.

I want to know if there is a way I can tell either with the computer running or all taken apart what the faulty part is. I don't want to buy both and then try swapping them out, or buy just the fan and realize that it was the logic board after all.

There aren't any symptoms that are unique to either part?