Fan not switching to high speed

Question

Level 1

19 points

Fan not switching to high speed

My MBP seems to have forgotten to switch the fan to high speed as it heats up. It did just fine out of the box but lately it seems to have lost this. I have ThermographX (a temperature sensing utility) installed and have seen temps as high as 174 F with no fan speed change. Any suggestions?

MacBook Pro 2.2ghz, Mac OS X (10.5.3), OWC Mercury On-the-go portable drive

Posted on Jun 27, 2008 9:05 PM

Reply

Answer 1

Jun 28, 2008 3:21 AM in response to TNJim

174 F is 78.8 C. My fans start to speed up when my core duo MBP reaches 75 C. The fan speed is not a low / high switch. The fan speed is based on the temperature. My MBP needs to get to about 85 C before the fans get fast enough to make a lot of noise.

Reply

Answer 2

TNJim Author

Level 1

19 points

Jun 28, 2008 8:55 AM in response to Retired Engineer

Yeh, I know there's no low/high switch. Just seemed a bit unusual to be that high a temp without changing to high speed.

Reply

Answer 3

Jun 28, 2008 9:21 AM in response to TNJim

Keep in mind idle speed is 2000 rpm and max is 6000 rpm. Idle speed has reasonable cooling power. No need to obsess over this. 😉

Reply

Answer 4

TNJim Author

Level 1

19 points

Jun 28, 2008 7:59 PM in response to neuroanatomist

You're probably right, I just want to be sure of what's normal and what isn't so that if there is a defect I can get it fixed before the warranty goes out (in less than 11 months). Most of the time the temp averages between 116-120 F. or lower. I just get a little concerned when the temps spike up like that and I don't hear the fans speed up.

Reply

Answer 5

TNJim Author

Level 1

19 points

Jul 4, 2008 10:55 PM in response to neuroanatomist

Hmm, guess I was just just a little paranoid about fan speeds. they do speed up, just not always to the full 6000 rpm's. The Istat widget has told me this. And you really can't hear them til they get above 4000 rpm. Thanks all for the advice.

Reply