Fan problems

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Level 1

0 points

Fan problems

Having fan problems with my MBP. On start up or wake from sleep, fans run all the way up to up to 6000RPM randomly. They stay at this speed until shutdown or sleep. The temp does not matter as it will do this when it is around 35C. There is generally around 95% of processor idle. I have reset the SMC and PRAM which did not fix the problem. It occurs when the computer is plugged into the power adaptor and on battery power. Any ideas?? I would rather not send it in again for another new logic board.

MacBookPro, Mac OS X (10.4.8)

Posted on Jul 14, 2008 11:12 AM

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Answer 1

iVmichael

Level 6

13,740 points

Jul 14, 2008 5:45 PM in response to mvrck5632

Run the Hardware tests on the Install DVD (hold d at Boot) and see if it reports any SNS (Temperature Sensor) errors. If one has failed (or the lead has come off) the fans will run at maximum rpm ...

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Answer 2

mvrck5632 Author

Level 1

0 points

Jul 16, 2008 8:05 AM in response to iVmichael

Thanks for the advice...I am having the disk sent to me from home and will run the hardware test when i get it. It has been okay for a couple days. I am guessing a sensor error because when the fan power up, My heatsink B is at -128C but if i sleep the computer it usually fixes the problem for a while.

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Answer 3

Shant87

Level 1

0 points

Jul 16, 2008 8:39 AM in response to iVmichael

guys i had the same problem 3 days ago...the hardware error code for that problem was : 4SNS/1/40000000: Th2H...took it to the service center and they fixed it...but now i have another error code: 4SNS/1/40000000: Th1H ..does this still have to do with the fans?

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Answer 4

Aug 1, 2008 3:22 AM in response to iVmichael

I had my screen replaced at an authorized Apple dealer, and afterwards the fans were at 6000 RPM at all times. Could it be that one of the leads came off - if so where are those leads and how can I fix it? I am having them take a look at it of course, but I want to know if I can fix this myself if need be because my confidence in this particular Apple dealer is pretty low right now.

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Answer 5

Feiafox

Level 1

5 points

Aug 12, 2008 8:44 AM in response to mvrck5632

hmm i m having the same fan problem for 1 1/2 year now. whenever i plug in the power adapter fans go up.

what i noticed is, that the memory controller and memory bank gets hot. The fans only react strange when the power supply is plugged in.

I had my logic board changed 2times.

I also think thta this whole thing somehow give me battery problems, since i had my battery changed 3 or 4 times, always because it would suddenly discahrge and then goin to sleepmode.. but thats a guess.

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Answer 6

orthorim

Level 1

10 points

Aug 12, 2008 5:28 PM in response to Nikolaus Heger

To answer my own question: Turns out one of the female temp sensor connectors came off the logic board. I don't know how. The only fix would be to replace the logic board but this machine is now out of warranty and the fix would be $1000.

My solution was to take the open source program smcFanControl and modify the code so that it sets min. and max. speeds in the smc according to CPU temperature. The background is that this is what OS X usually does, except it goes into failsafe mode when one temperature sensor has failed, as in my case. There are many temperature sensors in the MacBook Pro - iStatPro shows 8 working temperature sensors in mine. However, if just one fails, the system turns up fan speeds to 6000.

I am now just going by the one temperature that smcFanControl uses, and tuned the fan speeds so they are always on the safe side, e.g. higher than the original software would set them for any given temperature. As a result, my MacBook Pro is cooler than ever. I am thinking about releasing an updated version of smcFanControl with dynamic settings.

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