Thermal Paste Reapplied - Fans Always On?

[vv-tim]

So I reapplied the thermal paste (which was horribly applied) on my MacBook Pro today.

Now, first off I must stay... reapplying the thermal paste was quite a scary attempt. By the time I was halfway in, I realized that this wasn't something most people should try to do... but I already had spent $12 on the Arctic Silver and was halfway in... so I figured I'd keep going.

Now, first off... I'm idling at under 40 celcius. That's pretty awesome. It feels substantially cooler.

However... now my fans are constantly on! Perhaps I did something wrong... It doesn't bother me that much, since it being so much cooler is wonderful... but has it happened to anyone else? And if so, has anyone figured out how to get them to act normal again?

I don't really feel like opening her up for a third time (first time was to upgrade the HD)... so any help would be wonderful!

[lamina]

Ive never been inside a MBP (or any Apple laptop for that matter), but its possible the temperature sensors might me misaligned.

Shot in the dark, did you try resetting PRAM and NVRAM? (command-option-PR and command-option-NV on boot)

[Unorthodox]

Ive never been inside a MBP (or any Apple laptop for that matter), but its possible the temperature sensors might me misaligned.

He did say he was getting 40 Celsius.

[remowilliams]

You didn't by chance forget to reconnect the sensor like in the article below, did you?

http://www.macdevcenter.com/pub/a/mac/2006/05/23/thermal-paste-question.html?page=3

If I had the fans run constantly in my MBP17, I'm sure it would idle under 40c as well.

[vv-tim]

That might be it. I'm not sure I mind the noise or not... maybe I'll open her up tomorrow and check to see if I didn't attach it.

I could have sworn I checked them all though, haha.

Either way, I'm loving how cool it is on my lap now.

[wickedG35]

40 degrees celsius after reapplying thermal paste? I'm maxing out at around 40-41 without reapplying and I consider this hot (hot enough to prevent it from being on my lap as it will burn me).

I have the 17" MBP BTW.

[iKat]

40 degrees celsius after reapplying thermal paste? I'm maxing out at around 40-41 without reapplying and I consider this hot (hot enough to prevent it from being on my lap as it will burn me).

I have the 17" MBP BTW.

40 C really isn't hot enough to burn you. My MBP idles between 40-45, but usually it runs 50+. I use it on my lap all the time, just like I am now.

[wickedG35]

40 C really isn't hot enough to burn you. My MBP idles between 40-45, but usually it runs 50+. I use it on my lap all the time, just like I am now.

Well, not to sound too formal, but at my house I like to roam around in my boxers so the laptop sits on my bare legs and it burns. :)

When I wear shorts/pants, I feel the heat penetrate through. However, it isn't enough to make me want to take it off.

[lamina]

Check this out http://arstechnica.com/journals/apple.ars/2006/5/24/4100

In the 3rd paragraph it mentions disconnecting the heat pipe sensor. This is 98% your problem.

[Unorthodox]

Check this out http://arstechnica.com/journals/apple.ars/2006/5/24/4100

In the 3rd paragraph it mentions disconnecting the heat pipe sensor. This is 98% your problem.
What's is the other 2% of the problem? :p

My iMac G5 idles at 65 degrease Celsius.
And it's not hot at all. Im starting to wonder if something is wrong with my heat sensors...
And it only goes up 1 degree when it's under load.

You could always but a book under your MBP.
Actually Im not sure why more people don't do that....
That or keep burning yourself on your legs till you build up some nice thick calluses.

[mmmcheese]

Someone mentioned this link above (http://www.macdevcenter.com/lpt/a/6605) but it doesn't hurt to mention it again...

I have always thought that reapplying the thermal paste was really just a placebo effect....none of the other accounts I've read gave before and after results, just subjective conclusions ("it feels much cooler").

[vv-tim]

Thanks for the help guys. It was indeed the sensor. It got stuck under the logic board so I didn't see it when I was reattaching everything. I fished it out from under there after I took the screen off.

Still though, I ripped a CD and got the CPU usage up around 75% and I think I maxed out around 53 C. Right now it's running at around 45 C with the fans humming quietly.

Let me say, this is still a DRAMATIC decrease in heat from before. I'm quite pleased with my MacBook Pro's temperature now. I'll keep you updated as I use it into the day (as it sometimes gets increasingly warmer as its used), but right now it's running pretty quietly at a lovely temperature.

[remowilliams]

Let me say, this is still a DRAMATIC decrease in heat from before. I'm quite pleased with my MacBook Pro's temperature now. I'll keep you updated as I use it into the day (as it sometimes gets increasingly warmer as its used), but right now it's running pretty quietly at a lovely temperature.
Go through the test procedure at http://www.intelmactemp.com/ if you can, and post your temp results there. Around 45~50c for idle and 80c for full load (over time) seems to be the average "good" result for MBP17s.

[vv-tim]

Well, these are the results from CoreDuoTemp...

I idle at between 40-45 C.

@ 100% CPU load for about 5 minutes, the top I hit was 67 C, with it normally staying around 62 C.

Considering that after using the computer for most of the day I'd hang around 60 C or higher during normal use BEFORE the reapplication, I'd say it sure helped a WHOLE lot.

Granted, my fans do come on more often now. Most of the time they're on very low... but it's great.