Faulty Trackpad Sensor in PowerBook

by Stephanie Rewis on April 18, 2006

I've had my computer back long enough now to reliably report that it's been successfully repaired. Yes, I can conclusively say that replacing the topcase (or is it top case) and logic board has fixed all remants of narcolepsy. It hasn't fallen asleep one single time since I got it back last weekend.

For those of you that happen onto this thread (and without a doubt you've got a 1.67GHz PB — either 15" or 17") and aren't prepared to read the 80 or 90 comments on the previous two threads, here's my recommendation to you:

  • Install the little program called Temperature Monitor (it's freeware)
  • Set it up to keep the trackpad sensor temperature reading in the menu bar where you can see it at a glance. Also, be sure to set the history to record.
  • You can run the hardware test that came on your OSX disk, but it may or may not show anything wrong (if it does, it will likely be related to the logic board)
  • You will likely notice that when the trackpad temperature starts to wildly fluctuate, and then goes up into what is equivalent to the 200-something degree farenheit range, your computer goes to black screen. (Some can get it to wake up by jiggling the space bar or the shift key. Others have had to remove the battery.)
  • After you hit a phase where the computer will stay awake long enough, go to your system.log. You will see some comments like this:

    Jan 23 17:40:06 name-of-computer kernel[0]: Power Management received emergency overtemp signal. Going to sleep.

  • Save this in a text file so that you can show the correlation between the system.log information and the temperature history (which will show a big spike in temp at the exact same time).

When you talk to Apple about it, do not let them tell you they've never heard of it (the low-level person on the phone may not have, but you can get the problem escalated to a PowerBook specialist). Feel free to send them to these threads for proof. The comments of the other two threads are filled with people having the same problem. We can actually help Apple save money by sending them to this information. It has conclusively and repeatedly been shown now that replacing the Mother Board doesn't fix the sleep problem. There's no reason to replace the keyboard, the power supply, airport, wipe the HD and/or reinstall all the software. All those things have been done and none of them help.

All that needs to be replaced is the topcase and, most likely, the logic board (though it seems some may have been fixed with topcase replacement only — at least they haven't come back here to report problems with that repair).

I had originally thought my Powerbook was from the April batch. But when getting it repaired, I learned it was actually purchased in October, thus it was much newer than I realized. (My problems began in earnest in January when it was three months old.) This problem seems to manifest itself early in the life of these computers.

Good luck to you and happy repairing!

{ 26 comments… read them below or add one }

Gabe da Silveira April 18, 2006 at 4:44 pm

Congratulations. I dropped mine at the local repairship with explicit instructions to send to Apple (along with all my documentation). Nevertheless, they called me a couple days later after I went on vacation for 2 weeks to get ‘authorization to send it to Apple’, so it just sat for two and a half weeks until I called them back. Then they sent it in to Apple about 10 days ago (allegedly), so I hope to be hearing back REAL SOON.

Stef. April 19, 2006 at 4:29 pm

Oh Gabe — bummer! And it could have been already on your return. :(

Here’s hoping it’s fixed when it arrives!

Levi Albert April 23, 2006 at 4:13 pm

My name is Levi and I was the first person to notice this problem and post at the Apple discussion board.

My 17″ 1.67 was purchased in october/november and I called Apple as soon as the problem started.

They paid for my computer to be 1-day shipped back and forth (I had the computer back in my hands three days after I mailed it) with a statement saying they couldn’t find anything and that there were no problems.

However, since they sent it back I have not experienced any heat problems with my computer whatsoever. It is my opinion that they did something and just didn’t tell me (perhaps replaced the topcase and the logic board).

Oh well, that was quite a rant… i’m glad your problem is finally fixed.

Gabe April 27, 2006 at 12:50 am

Mine just came back today. Unfortunately due to the third party I have no information about what Apple did. However I can see that the topcase at least was replaced because the paint is once again brand-new.

I ran it 48 hours with nary a spike in the Temp Monitor. Hallelujah. Now time to buy AppleCare before the warranty expires.

Serfikon May 1, 2006 at 1:06 pm

I had exactly the same issue. Wildly fluctuating sensor information from the trackpad.


with pictures


Wayne Daly May 6, 2006 at 1:51 pm

Hi there, I’d just like to add my name to list of people who have had this problem resolved, and would like to thank you for giving me a straightforward solution. My Powerbook was doing this intermittently for a few months and finally became unbearable. Temperature Monitor confirmed the problem. I’ve had my top case replaced (and nothing else as far as I know), and everything’s back to normal. I’m sure this has been covered already, but if anyone else has this problem, make sure you have installed Temperature Monitor to show the technicians at the Genius Bar, and, if possible, print off a screen grab of the ‘overtemp’ message in the console. None of the techinicians had encountered this before (that’s not a criticism – they were really helpful and turned around the repair in 4 days!). It just helps both you and them if you have as much evidence as possible.

Thanks once again!

ponce de leon May 19, 2006 at 1:29 pm

This same problem started happening to my PB (1.5 Ghz, 15″, 10 mo old) a week ago. I was traveling and couldn’t do much about it, but I managed at one point, when I could keep the PB awake for about a half hr, to read the discussion groups, and found that others were also experiencing this “narcolepsis” problem. I used “Temperature Monitor” to track the sensor temperatures, noting the wild trackpad reading. I also made a printout of the “Power Management received emergency overtemp signal. Going to sleep.” message found in the console. I then took this printout and my PB to the genius bar in SOHO, NYC store, but I didn’t have an appointment, so I couldn’t see anyone. I headed to the TEKSERVE (on 23rd street), where I had purchased the PB. I was taken care politely, and I showed them the evidence and waited for them to run some tests. After about a half-hour their representative came back and told me that I had disk fragmentation and that I needed to reinstall my OS! That this was a “software problem” and that since Apple warrantee didn’t cover software problems that I could either resinstall the OS myself or they could do it for about $145 (I don’t recall the exact quote as my own temperature was starting to fluxuate upwards). I asked the representative (Ripley) if she had ever ecountered this problem before, and she seemed to give an ambiguous answer. So basically they refused to look into my problem. Ms. Ripley, claimed that the PB hadn’t gone to sleep while they were running their tests. I explained that this malfunction of the sensor occurs erratically. So I still haven’t been able to get my PB fixed. Any suggestions would be greatly appreciated. Thanks.

Colin Burns June 6, 2006 at 5:39 am

I too am having the same problem. Took my laptop in last week, but they couldn’t replicate the problem. Today I set up a video camera right behind me to ensure I could prove something was happening.

I have printed out the system.log file, and have installed and am currently tracking the trackpad temperature to support the evidence here.

Hopefully they will simply replace the required components and I can get back to work.



Jay June 7, 2006 at 8:49 am

My Powerbook started this behavior two days ago. It was bought in June of 2005 and as of yesterday I have 22 days left on the warranty.

A few questions…

If I call/email Apple Care now will I be able to get this fixed after the 22 days are up since I reported the problem early? I’m a tech guy and I hate sending things away for repair if I can help it.

Has anyone else tried looking under the top case? Maybe that ambient light sensor trick? Perhaps just the removal and replacement of the top case is enough to set things straight?

I do have an Apple Store close by, maybe I just need to go there.

Is ProCare tied to an individual or a specific machine?

Stef. June 7, 2006 at 9:37 am

Hi Jay… welcome to our little sleepy corner of the world. ;)

A few answers for you — I believe the answer to your first question is, “yes, if you have already reported it, it should still be covered.” (But please verify!)

I don’t know of anyone that looked under the topcase… my understanding was that if I got in there, I voided my warranty. I wasn’t willing to do that. :)

Procare is tied to an individual… so if you have four machines, you’ve got it on them all. You can make your appt ahead of time and get a priority repair if they opt to do it in store (but it’s almost a given that they’ll have to order the parts… that said, if you’re close, that’s no biggie. For me it was a pain. ;) )

Good luck to you Jay… print these threads out, have your temperature monitor history and your system.log showing the overheating… you should be good to go. :)

Jay June 7, 2006 at 12:30 pm

Thanks for the welcome Stef.

Actually since I do maintain a site for a non-profit I volunteer for using Dreamweaver I’ve already subscribed to a few of the RSS feeds. :)

Back to the matter at hand…

I wasn’t aware popping the case would void the warranty. So a user can’t change the HD and DVD themselves since there are no access doors?

In any event I was referring to this site somone posted at the end of the comments on the first thread.


I just hate the thought if dropping my PB off somewhere. I really wish Apple could send me the parts and I could repair it in an afternoon. I work on Cisco routers and switches, I think I can handle a little notebook. :)

Thanks for all the advice! I did a crude backup of my system last night and have been wanting to get FolderSync3 for a while so now it’s time to bite the bullet. Hopefully it will stay awake long enough for me to actually use it.

Rick Cameron August 6, 2006 at 1:49 am

Hi, I’ve set up a blog dedicated to resolving this problem. I will attempt to list all the fixes that are reported to work. I have just read a post from the owner of a titanium PB having the same problem….so that kinda stomps the theory that this is a hardware only thing. I personally suspect that we have a firmware or OS X code problem that is causing the trackpad sensor to read high.

My posts above cover my reasoning but they are scattered thru the discussion and so a bit hard to absorb. I’ve described a temporary fix that works for me on the blog…. no hacking code or opening the box required.

I’ve been calling the problem ROSS or Random Overtemp Sleep Syndrome but on the new blog and the associated mail group, I’ve renamed it “Narcoleptic Apple Puzzler” or NAP. The idea is to lobby Apple in a positive way to fess up and fix this for all owners regardless of their warranty status.


I’ll link this discussion board and others to the Mail Group page and also post all cures that seem to work. I’m not up to hacking my system code and would rather wait for Apple to fess and fix but some owners have posted on how to do this…. only for the brave.

Paul Robinson September 24, 2006 at 1:22 pm

My 17″ Powerbook just started to fall asleep by itself. Thanks for all the good information.

After watching the Trackpad temps. go all over the map I reset the PMU and decided to leave the battery out and run off the adapter. The computer ran a solid 1.5 hrs last night while I did a complete backup. I slept it overnight and it woke normally this morning. The trackpad temp. now is a solid 77.0 degrees F but doesn’t vary so maybe the software can’t monitor it with the battery out. So far no sleeping. I’m hoping this is going to last. Will keep you informed.


Rick Cameron September 24, 2006 at 8:12 pm

Yikes! posted to so many threads that I missed updating this one. Had to revise my NAP web link after some glitches with iWeb and it is now:http://web.mac.com/rickcameron/iWeb/Electric%20Lamb/N.A.P./N.A.P..html

We are getting more members every day for our .Mac NAP support group. If anyone would like to join, please email me so I can send you and address.

Paul Robinson September 29, 2006 at 4:22 pm

This is a follow up to my previous post regarding a possible short term solution to our problem by removing the battery. The fix worked perfectly for about five days with the trackpad tempeature a constant 77 degrees. Then yesterday, with the battery still out, the sensor came back to life and began its wild fluctuations again. This led to 3 unrequested sleep episodes and a very ugly trackpad temperature curve as well as the usual system log shutdown messages. So, taking out the battery doesn’t solve the problem.

I shutdown, reset the PMU and all day today the trackpad has been reporting 44.6 degrees.

sai October 29, 2006 at 8:11 am
Rick Cameron October 29, 2006 at 8:48 pm

WOW! I had a feeling that something like this must be possible. Awesome that you had the courage to rip out wires on the sensor. Even better that it works! The photos are great but can you tell us which wire you ripped out exactly? Do you have a macro image of the “final cut”? Ready to try this myself but heart in mouth and would appreciate some more info.

Blankenship April 27, 2007 at 10:06 pm

After trying every software fix I could find (deleting all those .kext files, etc.) and it still nodding off, I finally opened it up and ripped out the little offending sensor. Well worth the trouble! It’s finally working fine for the first time in a month. Rip that thing out! Hang it above the mantle next to the deer heads! I’m finally happy again.

Benoit June 6, 2007 at 6:32 am

Instead of replacing hardware, an other good solution is to disable the trackpad temperature sensor logicaly. That works well!

With an administrator user, open a Terminal and type :

$ sudo mv System/Library/Extensions/IOI2CLM7x.kext System/Library/Extensions/IOI2CLM7x.kext.DISABLED

And then reboot your Mac.

I found this solution on this forum : http://www.macfixitforums.com/printthread.php?Cat=&Board=Forum35&main=731197&type=thread

Yo June 29, 2007 at 8:48 pm

No, it won’t work. I’m talking to the guy above.

Removing the faulty sensor inside under the trackpad is the only and the fastest cure which will not mess up your computer if you do it right.

JP July 9, 2007 at 2:42 pm

Do NOT open the computer and detach the sensor. There’s no reason to. Here is the complete method for disabling the sensor:

Move (do not delete) the following extensions to a different location (a new folder outside the extensions folder). You’ll find them in your system/extensions folder:

* IOI2CControllerPMU.kext

* IOI2CLM7x.kext

* AppleLM7x.kext

* Extensions.kextcache

* Extensions.mkext

Once moved, restart, and that little sensor will be disabled.

Billyo October 24, 2007 at 5:36 am

Can anyone verify that the above works?

I’m at my wits end with my Narcoleptic PB G4 and I don’t have the balls to open it up and rip out that chip. Though I might have to.

How much does a topcase replacement cost out of warranty?

Shawn November 10, 2007 at 11:20 pm

Hey. I just upgraded my 15″ powerbook with N.A.P to leopard. And I think it may have fixed the problem. Can anyone confirm this? I think apple might have disabled the trackpad sensor in leopard. When you use 3rd party software to get readings on it, it shows up as not available

nicorojas December 7, 2007 at 3:13 pm

I had this problem six months ago, but after deleting the extension file for the trackpad sensor, it dissapeared. However, I upgraded to Leopard two weeks ago. The problem was back within a week. I again removed the extension file, but the problem returned last night even though no trackpad sensor is listed and temperature monitor shows no sign of overheating. The console log shows the usual: overheating.

Any comments? I really need the help, I’m using the powerbook to record my band this sunday. If I don’t find a solution I’ll have to take drastic measures and rip off the sensor, but I’mj kinf of afraid of doing it.

Nicolas Rojas December 14, 2007 at 9:42 am

so, I removed the sensor….now, everything is working as it should!!!

powerbook October 23, 2008 at 10:09 am

without a doubt you’ve got a 1.67GHz PB — either 15″ or 17″) and aren’t prepared to read the 80 or 90 comments on the previous two threads, here’s my recommendation to you:you can find


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