Chosen Solution

Dear all, I recently replaced the logic board on my Mac, now I have this fan constantly on at 6000RPM all the time issue. So I did an Apple hardware test using the installation disk that came with my Mac and got this cryptic error: 4SNS/1/40000000:Th2H-128.000 After some googleing I came across this: Th2H Right Fin Stack Proximity Temp My question is, is the Th2H Right Fin Stack Proximity Temp the Right Thermal Sesor, or does someone know what part the Right Fin Stack Proximity Temp refers to? Thanks in advance. Tim.

Hi man download this app http://www.macupdate.com/info.php/id/230… Then from the terminal, type in the second line (4000): /Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 60e0 (that’s the default 6200 RPM) /Applications/smcFanControl.app/Contents/Resources/smc -k F0Mx -w 3e80 (That’s 4000 RPM Max) You obviously gain a few degrees C when limiting to 4000, but at least your MBA shuts up. Had the exact same problem, was so glad i found this

Dries, I have a question for you… I have an iMac 7,1 2.4GHz C2D running Snow Leopard. The fans run on full speed continuously. I have had it checked out and it is diagnosed as “fails CPU temperature diagnostics – always over temp” In other words, as soon as the computer starts up, the fan(fan sensor) thinks the CPU is HOT and runs the fan full speed. I tried your second line as above, but i get this message in terminal “command not found”. Is there something else I should enter at the terminal command line for my iMac? I’m desperate for help. It’s either find a solution or trash the iMac!

This worked for me too as I’m having the same problem. Wondering if you resolved it? You said you would post back.

Hello dries thanks for your answer, I used it and it works on a macbookpro 3,1. Would you by any chance know how to get the fans turn to 2000 rpm ? Because it’s a bit noisy at 4000 rpm. Thanks in advance André

Hello. Just used your tip, and my (almost) constant 6200 RPM turned into 4000. First relief in weeks. Thank you so much. 2 Questions though:

  1. Is there a way to set the limit even lower (say, 3300) ?
  2. How do I make the terminal command permanent than having to repeat the command after every start up? Many thanks, Ayelet

I understand there are ways to manually control the fans but does anyone actually know the location of the right fin stack temperature sensor or anything else about it?