Help needed diagnosing hardware failure (fan suspected)

[damienallen]

I was using my T42p (2373-P2U) when I head a small pop followed by my fan shutting off. I immediately killed power and removed the battery. While inspecting the case I noticed smoke coming out of the fan vent. Fast-forward 15 minutes and I have the keyboard/palm rest removed. To my surprise there was no visible damage in or around the fan despite the smoke. I smelled around and from what I can tell the smell is strongest at the fan itself.

I don't want to order new parts without a second (expert?) opinion. Is this enough evidence to order a new fan? Is it common for the T4X fans to fail? Are there other components near the fan that could have burnt out without the computer shutting off?


Almost forgot to mention that this is the fan/heatsink that covers the CPU and GPU.

[rkawakami]

Welcome to thinkpads.com!

I think I know the "pop" of which you speak. Since I can't smell what came out of your system, my best guess is that it was part of the plastic packaging that surrounds a transistor or IC. Look at any of the black square/rectangles on the motherboard, even if they are nowhere near the fan, to see if the surface is charred, pitted or missing , like this:

http://www.rkawakami.net/ibm_t2x/let.jpg

If so, then there's not much you can do besides replacing the motherboard. Even if we assume that the part can be correctly identified, sourced and installed, there still might be a problem on the board which would cause the replacement to do the same thing. Sometimes a semiconductor (transistor or IC) will blow first, thus preventing the fuse from doing its job. If there's a short somewhere on the board and it is not found and removed, then the same thing will probably happen again.

If it was a fuse that burned out, then check F4. A member here has posted this: http://nickpaton.fireflyinternet.co.uk/ ... 0Fuses.pdf (ref: http://forum.thinkpads.com/viewtopic.php?f=2&t=85311 )

On the other hand, if the fan indeed burned out the windings and there's nothing else wrong with the motherboard, then they are fairly cheap on eBay. FRU 26R7860 (14.1" short fan) can be had for under $20.

[damienallen]

Thanks for the quick reply and very useful information on what to look for. I ended up removing the fan and it is definitely the source of the smell. I inspected the motherboard and found no damage, so I think I'm in the clear. Also, I do see a small circuit board within the fan casing, so it could have happened there. My fan is the slightly more expensive 13R2657 which I'm guessing has to do with the GPU. Order placed on eBay this morning!

Thanks!

EDIT: Found it

[Norway Pad]

Ouch. Interesting picture, let's hope this little "pop" didn't blow a fuse on your mobo. Post and let us know how this turn out when you install your new fan.

[damienallen]

I just got the new fan and popped it in. Booted up just fine and the diagnostic BIOS mode didn't find any problems. I'm glad it was just the fan.