MBP 1st Gen. Only One Fan

What is the Model Identifier of your MBP, as shown in System Profiler > Hardware Overview? It will be a two-digit number in the form "X,Y".

Your MBP has two fans, as the top photo on this page shows:

http://www.ifixit.com/Guide/Repair/MacBook-Pro-15-Inch-Core-Duo-Model-A1150-Logi c-Board-Replacement/498/4

Unfortunately, I don't know whether both are always supposed to run simultaneously.

I also have a 1Gen MBP (MacBookPro3,1--or "Late 2007') and have used iStat Pro since the computer was new. Mine has never showed only one fan running. I think you've had one die.

The downsides to not fixing the fan are:

1. The functional fan will have to work harder and could also fail from shearexhaustion.

2. Cooling with one fan is inefficient and could cause an overheating failure of components normally served by the non-working fan.

If you live in North America, ask for a "Depot Repair." Instead of fixing the computer in the shop where you'll get a charge of from US$700-$1100 for, say, a logic board, they will send it to a central refurb facility for repair at a flat charge of about US$315 plus shipping to fix anything that's wrong as long as the case does not show signs of physical abuse or drowning (beer stains under the keyboard kills the deal).

A depot repair takes longer that the in-store repair (usually about one business week) but the cost savings is well worth the wait. Most people here who have exercised this option report getting the computer back in about one business week and are very happy with the outcome.

"The question now is "what is bad - the fan or whatever is supposed to turn it on!""

A very good question indeed. Various sensors control the fans. Apple Hardware Test (AHT), which came on one of the optical disks packed with your computer, will detect bad sensors. Although the codes are cryptic and no one has even posted a list of codes with their significance, I know that sensor failure codes from AHT have the letters "SNS" embedded in the code. A bad fan motor is a different code but I can't remember it at the moment.

A bad sensor is probably not as easy a DYI project as a dead fan.

Hopefully the fan is simply clogged with dust or needs lube. I had a tiny cooling fan on a old video card seize up. ATI could not supply a replacement so I removed the fan, peeled off a sticker and found myself looking at its bearings. I lubricated it with---wait for it--trombone slide grease! It's a very light and clean product. The fan stopped it whining (literally) and is still working today, many years after my misguided repair

A fan failure will be reported by AHT as a code including "MOT". Running AHT would be well worthwhile. There is no other publicly-available diagnostic software to use.

Apple Hardware Test (AHT) is proprietary hardware diagnostic software, found on one of the DVDs that were originally shipped with your machine (the disc label will tell you which one it's on). Because it's machine-specific, it's not present on any other disc. So find the disc that contains it and start up from that disc while holding down the D key on your keyboard until the AHT startup screen appears. Run the short test, and if no error shows up, run the extended test. Post back with results.

That's the fan itself. Where are you located?

Contact any or all of the following parts suppliers:

http://www.pbparts.com (parts and repair work)

http://www.dttservice.com (parts and repair work)

http://www.powerbookresq.com (parts and repair work)

http://www.tekserve.com (parts and repair work)

http://www.powerbookmedic.com (parts, repair work and instructional videos)

http://www.welovemacs.com (parts and used equipment)

http://www.ifixit.com (parts and excellent, illustrated online take-apart instructions)