Fans blowing full blast during sleep

My MacBook Pro (15", 1.83GHz) will turn its fan on +full blast+ whenever it sleeps. This happens immediately, and regardless of whether the lid is closed or not. The computer goes to sleep fine from the Apple menu, and the indicator light pulses (i.e., I think it is really asleep). I've let it go all night long, and the fan never seems to stop. I can get good temperature readings from all the sensors, and the RPMs on both fans look reasonable while the computer is awake. They also modulate in a normal range during use. I haven't had any other trouble with it.
Originally, this computer was salvaged. It wouldn't turn on or charge. I replaced the left I/O board (containing the DC board), and it works fine now. I can't think of what would be causing this, but I'm open to consider that I didn't plug something in correctly as I was reassembling the laptop. I also don't know what caused the original failure of the left I/O board... so I'm not ruling out weird water damage or something.
Any ideas are appreciated. Thanks.

Hi Bill. It is worth bearing in mind that the "default" on most Macs if the OS thermal control routines can't be accessed, or if data from a sensor is not available, for example, is to send the fans up to maximum revs.
Usually when people experience the "full fans during sleep" situation it is because the system is actually "crashing" when sleep is attempted. In such situations , of course, the computer fails to actually "wake up" when asked to and has to be force shutdown! I gather this isn't the case with yours? It wakes up normally and the fans return to normal speed when it wakes?
If the OS isn't loaded (or isn't getting the right readings) , of course, the fans go into hyperdrive anyway (hence the flat out activity when running the Apple Hardware test and the like)
It sounds almost as if the computer is losing effective "Operating System control" and going into "hyperfan" mode accordingly when sleep is activated, but not actually crashing, and then recovering control on waking.
I presume you have tried things like wiping the drive and re-installing the OS from scratch and a PRAM reset as well as the SMC reset already mentioned?
Cheers
Rod

Similar Messages

  • IMac fans blowing full blast

    From the moment I switched my Dual Cure i5 iMac on this morning, the fans have been blowing full blast.  While the house and office have been warm (80 degrees), it's nothing unusual.
    Not sure if I need to let it keep running to get some cooling air flowing through; or shut it down to cool it off (I let it sit about 3hrs., turned it on and the fans immediately went back onto full-blast-mode), or if the fans are on their own here.
    The exhaust coming out if warm, but not unusually so.  Earlier it was hotter but seems to have cooled off a bit.
    Any suggestions?

    Please do a SMC reset.
    SMC RESET
    Shut down the computer.
    Unplug the computer's power cord and all peripherals.
    Press and hold the power button for 5 seconds.
    Release the power button.
    Attach the computers power cable.
    Press the power button to turn on the computer.
    Roger

  • Random Overheating/Fans Running Full Blast

    Hi there,
    Ever since I received my Early 2008 Mac Pro a couple of months ago, it would randomly begin blowing the fans at full blast and continue to do so no matter which OS I boot to, Mac OS X, Windows, or even Linux discs. iStat Pro reads that my Northbridge is running at 249º F, which is completely ridiculous, since all of the internal components to the machine are running very cool. This Northbridge sensor is appearing to throw the fans into overdrive. It sounds like I'm working next to a vacuum cleaner. It's very loud and irritating to work next to.
    Unfortunately for me, I don't live near an Apple store, or have the means to get to one. Apple also will not let me send in my machine. About a month ago I had the chance to drop my machine off at an Apple store, but the geniuses were very confused about the problem. 2 Weeks later I received a phone call explaining that my problem was fixed. They never explained to me how the problem was fixed. I had a friend drive out to the Apple store and pick up my machine for me, but when I turned it back on, it still ran full blast. Nothing was different.
    I came back from work one day and to my surprise the machine was completely silent. It has been randomly going from full blast fan speed to normal fan speed ever since, fixing itself every few days. I have 0% CPU usage at all times, yet the machine thinks it's overheating.
    So now I ask you, Apple Discussions Board members, what can I do to resolve this annoyance? I have:
    Reset PRAM
    Reinstalled Mac OS X
    Unplugged the computer for days on end
    Swapped Hard Drives
    Taken RAM out
    Tried SMCFanControl
    Taken out that little CR2032 battery on the mainboard
    And no luck. Help is appreciated!

    Yesterday I popped in my disc and did an Apple Hardware Test. It passed with flying colors after hanging up and appearing frozen for 10 minutes. Found that little button behind riser A and pushed it for 5 seconds, rebooted a few times, unfortunately it did not work.
    Also where is the Apple Hardware Monitor? Are you sure you don't mean Activity monitor? I couldn't find where the temperature/fan readings are in Activity Monitor.
    The fans turned off, however, today when my computer woke up from sleep mode. They were off for about ten minutes when all of a sudden the fans kicked on full blast. This was strange because the computer would usually gradually increase over a 15 second period... not immediately. So now it's still stuck here, making noise :\

  • My MacBook Air 13' (2013) will occasionally start the fan at full blast, not connect to any wifi or detect any wifi, and will remove the battery icon from my menu bad as well as tell me there is no battery connected. How do I fix this?

    My MacBook Air 13' (2013) will occasionally start the fan at full blast, not connect to any wifi or detect any wifi, and will remove the battery icon from my menu bad as well as tell me there is no battery connected. How do I fix this? I have restarted my computer multiple times, **** it down, and ran a diagnostic test to tell me nothing is wrong and my computer is not running any applications. There is no reason for the fan to be on full blast! when I try to set the option to show my battery icon in the menu bar, it will automatically uncheck. How do I fix all of this?

    Have you tried SMC and PRAM resets?
    http://support.apple.com/kb/HT3964
    http://support.apple.com/kb/ht1379
    Ciao.

  • HT3964 I followed the steps here, but I still cannot get my iMac to stop runnin the fan at full blast. What now?

    I followed the steps here to reset the SMC, but I still cannot get my iMac to stop runnin the fan at full blast. What now?

    Ensure you are  using the SMC reset for an Intel iMac. Sometimes it take several tries back to back for the SMC reset to work. I've included a link to the correct instructions for an Intel iMac (just in case) , click https://discussions.apple.com/docs/DOC-3603.
    If you still have issues then run Apple Hardware Test in Extended Mode at least 3x, it's  also possible you may have a damaged fan or fan sensor.

  • Powermac G5 Dual 2.0 thermal calibration issue - Fans on full blast!

    Hello, I need to do thermal calibration on powermac G5 dual 2.0.  Does anyone know where to get ASD dual 2.5.8 discs? I'm afraid to run the computer with fans on full blast.  Any help would be greatly appreciated!

    Hi, ASD has never been available to the public, but even if somebody had any clues or other suggestions, you & Apple are the only ones that can see your eMail in your profile.

  • Can't wake up my iMac in the morning and fans going full blast

    Several times in the morning, after leaving my iMac on all night, I've found the machine asleep and the fans going full blast !?!
    This in a cool 68 degrees room.
    I then had to turn the iMac off manually and restart. I had a failed power supply replaced in April and am covered under the Apple care program (thank goodness !!!).
    Could this be the logic board overheating now ?
    Thanks for your help- Jim Vaughn

    Hello Jm - it could well be another thermal problem, take a look at your Console logs and see if anything jumps out at you.
    Since you do have Apple care (wise man) I suggest you call them and have them deal with the problem.

  • Sleeping G5 often makes fans run full blast and machine unresponsive

    the only thing new lately is that I installed Leopard 10.5.3 on my dual 2.0 GHz G5 tower.
    I usually sleep my machine all the time
    now it's a crapshoot whenever I sleep it whether or not it will go to sleep normally, or freeze in a state of screenless unresponsiveness with the fans running on full blast with no way to stop except a hard shut down or power kill
    other than this the machine is literally working just fine. Never interferes with my work.
    I don't know if this is 10.5.3 related or not, but I do wonder.
    I started up from an applecare disc and did a full diagnostic and everything checked out
    I guess I'll have to test Tiger sometime again but that'll be a pain because I'm already addicted to Leopard
    I just hope this old faithful tower isn't going dead on me. and I wish there was some official word if this was just a 10.5 thingy

    I believe I have solved this problem for now.
    I opened up my G5 and used compressed air to blow out all the months of dust buildup in the machine.
    I re-seated every single removable component inside (RAM, PCI cards, graphics card, etc)
    I also pushed the PMU reset button once and then put the machine back together.
    I proceeded to sleep it and wake it up about 5 times in a row, and it didn't exhibit the blowing fans problem and the light was "snoring" as it normally should in sleep mode.
    A few days later, the machine hung up after being put to sleep AGAIN with the fans kicking up and the light on my cinema display staying one dim level without the "snoring."
    This time I disconnected my Belkin USB hub and I have not seen the problem resurface since.
    The interesting thing is that cleaning out the machine and resetting the PMU sure seemed to help.
    So maybe it was a combination of things that were the culprits.
    I also wonder if I can ever use this perfectly good and only 1 year old Belkin USB 2.0 hub ever again.
    My father uses the same model on 10.5.4 as well on his MacPro without any problems. I am on a G5.
    I wonder if there's a firmware on the Belkin USB hub that could be in need of upgrading or if I simply cannot use this hub w/ this computer anymore.
    (luckily I don't need it urgently right now)
    I will report back if the problem happens again, but for now, since the computer has been sleeping totally fine for days now since removing the USB hub, I am marking this question as answered and hope that this info can help other people.
    If anyone has anything to add to this thread or knows about the specifics I've discussed above, please feel free to respond more.
    Thank you

  • G5 Quad, fans @ full blast & random sleeping..

    I'm using a PowerMac G5 Quad, 2.5ghz, running OS x 10.5.8 I have a problem with random sleeping,
    (the Mac, not me LOL). Sometimes it will go for days, run all night, with no problems.
    Then it suddenly goes to sleep. It's not overheating, I've cleaned it out regularly & have temp monitor running.
    It has done it within minutes of starting up. After it goes to sleep it can be woken with a mouse click of keyboard stroke,
    and 9/10 times everything is where it left off. It has crashed, but comes back OK.
    I have read a lot of stuff about firmware updates, but not sure wether to proceed.
    Another symptom is constantly noisy fans.
    How can I tell which firmware is running on the machine now?
    Can anybody advise a course of action?

    mrchrishouse wrote:
    OK I,ve found my boot ROM version, It's 5.2.7f1 which is higher than any mentioned in any updates.
    I've zapped the P RAM and Reset the NV RAM...
    Still have fans @full blast at all times.
    What controls the fans? Is there somthing else I can re-load or reset?
    There's always the SMU reset: http://support.apple.com/kb/HT1436
    The fans are controlled via the SMU, which has a watchdog timer running which is reset when control comes from the CPU running the system piece that monitors the thermal state of the machine.  That is why, when the system tanks, the fans will firewall as a safety measure.

  • GeForce 8800 GT Fan running full blast

    Hey there folks,
    I have a Mac Pro (early 2008, MacPro 3,1) with the OEM Nvidia GeForce 8800 GT graphics card.
    Last night when I got home from work I booted up the machine and the fan on the 8800 came on full blast, it has always done this for 3-4 seconds on boot and would then spin down again. The thing is this time it never spun down, it kept going full blast and has ever since. The card is not under heavy load and is cool to the touch. The fan keeps going full speed so long as the machine is on, regardless of activity. Only when it goes to sleep or is shut down does the fan stop.
    I've tried resetting the PRAM, resetting the SMC, and even ran Apple Hardware Test and it returned no errors. I have iStat Menus installed but I don't believe it is capable of showing feedback on the card. I haven't been able to find much online about this issue and there are apparently no Mac versions of Nvidia's control and monitoring software for their cards.
    I took it into the local Apple store today and the Genius Bar almost immediately told me its a flat-out replacement issue. The machine is out of coverage so ordering a new copy of the same card is expensive ($380). I've looked into other, newer cards like the ATI 5770 or 5870 through Other World Computing and they seem like good options.
    Has anyone else come across this problem or know of a workable solution?

    I replaced the card. At first I took it to the Apple Store but the person there said its basically just a somewhat common hardware failure on the card. Not much to do but repair or replace it.
    Rather than spend the time and money to have them diagnose it further just to tell me the same thing I replaced it outright with a card from Other World Computing; the ATI Radeon HD 5770. IT was a good alternative for my machine which, due to it's hardware configuration, has only a few to pick from as viable replacements. It's been working fine so far, no complaints. Just be aware it is a BEAST of a card and puts out a lot of heat.

  • Fans at full blast after disk exchange

    I recently swapped out the internal disk of our early 2006 intel imac using the instructions on ifixit.com as the earlier disk was in its death throes. The repair, although a little complicated went without incident and I installed a new 1 TB disk in place of the original. After restarting the machine after the repair, the fans ran at full blast. I thought this might be due to the disk temperature sensor not being firmly attached to the disk and took apart the machine again and ensured it was. Istatpro read temperatures of 27C for ambient and 34 C for the hard drive. From this, I assume that the hard drive temperature board is connected correctly, right? The two cpu cores read 37 and 38 C respectively; values that seem very much normal to my eye. One odd thing I had noticed was that istatpro displays "CPU A" and "GPU A" voltages, currents, and power. In my case, the power is displaying normally (somewhere between 3-10 watts depending on the load), but the current and voltage always read zero. I also did attempt to start from the diagnostics disk that came with the mac (Tiger), however, although I had disconnected everything but the keyboard and power and pushed the "d" key during boot, the machine started up from the hard disk after a brief detour. I have never had to use the hardware diagnostics disk before so perhaps there is a special trick to get it to work. I should also add that I hopefully reset the SMC controller by again disconnecting everything including the 100 V line and pushing the power button for about 10 seconds. No change. The fans keep turning.
    Any ideas?

    I just took the iMac apart again (I am typing on it now as well). The connector from the hard disk measuring pc board to the main logic board is fine. I looked at both ends carefully and the pins are straight, the wires fine. I was careful in taking it apart and putting it together again. My working assumption now is that I have unintentionally disturbed some other sensor on the board -- one that I did not knowingly touch. I note that in istatpro that there are "CPU A" and "GPU A" voltages, currents, and power readouts. While the power readouts for the cpu/gpu look correct, the current and voltages are all zero. I must admit that I am still somewhat concerned that the daughterboard that measures the hard disk connector is not working correctly, but I have no proof of this. Programs I have downloaded from the internet (TemperatureMonitor etc.) seem to indicate hard disk temperature using the S.M.A.R.T. status and do not apparently use the daughterboard at all. Is there a program that will give me the readouts from the daughterboard attached to the hard disk so I can be sure that it is working. As a last resort -- is there a program that will let me lower the speed of the fans to something reasonable if the feedback is really broken. I have a feeling that Apple will charge a lot for this sort of repair -- hardly worth it for a four year old computer.

  • Powermac G5 Fans Running Full Blast

    Hi, I read several posts about fans but do not have any crash or freeze issues associated with the fans in my G5 server constantly running on high... Fans are on full blast for two days now, no software updates or hardware changes have been made to the server
    Other than the Fans running the computer is working fine
    Here is what I have tried so far;
    • shut down and unplugged power cord for a few minutes
    • disconnected Ext FW drives
    • cleaned out dust from inside case (very little)
    • checked fan connection (dual fans)
    • reset SMU
    • tech tool pro test
    None of the above has had any effect. The only thing that will shut the fans down is putting the server to sleep. Sleeping the computer knocks everyone off the server so that is not an option -
    Any ideas would be appreciated
    Thanks

    A fan issue is usually related to the SMU. I see that you tried that, but if you used the +push the button on the motherboard+ method, try the +unplug the power cord+ method as described here
    http://support.apple.com/kb/HT1436
    under +Power Mac G5 (Late 2004)+. As stated, "wait two minutes." It does not say "at least" two minutes or "about" two minutes.

  • Intel Mac Mini fans run full blast even when off

    Hi All,
    I have gone through the forums and haven't found an answer to this one. I have an Intel Mac Mini running the latest updated Tiger that I use solely for a media center.
    About a week ago, the box started running fans full blast, regardless of whether it was actually turned on or not. As soon as it is plugged in the fans blast.
    Otherwise, it seems healthy, and boots normally.
    The steps I have taken so far include resetting permissions, verifying the disk, and resetting the SMC in the proscribed fashion.
    After this occurred, I downloaded and installed smcFanControl from Lifehacker.com. This reported fan speed of zero and Temperature of zero.
    Next I opened the case and insured the fan/HD cable next to the lttle battery was securely fastened as this had been reported to cause this symptom.
    What's next? The device is out of warranty and honestly, I don't want to spend any money if I can help it.
    Should I take it apart further and see if the other end of the fan/HD cable has somehow worked loose?
    Can anyone think of another cause besides a loose cable?
    What if I completely disabled the fan? The hardest thing I ever ask it to do is run iTunes and VLC.
    Any advice is greatly appreciated.
    Dave

    I have refurbished two G5s with LCS and screaming fans (this was avery common problem with G5 LCS macs), the red light on the motherboard could mean the CPUs need to be re-seated. This red LED light appeared on my mac after I had removed the CPUs to add new thermal paste.
    If you have done all the necessary basics with no sucess here are a few things to try next.
    1 - Coolant
    As BDAqua mentioned above, coolant evaporates and often leaks at the 'O' rings, to check this you will need to remove the CPUs from the LCS and check for crystalisation (white rice). If you have leakage, it will be time to drain the block, add new coolant and 'O' rings. This is tricky to do but there is lots of info here and on other sites to help you.
    2 - Thermal paste
    Replace the thermal paste with Artic MX4.
    Try the above and let is know how ou get on.

  • Fan on full blast!

    I was having problems with my mac freezing up & not opening apps, or any windows whatsoever, so I tried to restart it by pressing the button. Now, when my imac starts up the fan goes to full blast and it just gets stuck on the opening apple screen. Please help my baby! lol

    Hi Macjaxi and welcome to the forums!
    Sounds like it needs a bit of TLC and maintenance, as well as updating to 10.4.11!
    Repairing permissions is an important part of regular maintenance, and should always be carried out both before and after any software installation or update.
    Go to Disk Utility (this is in your Utilities Folder in your Application folder) and click on the icon of your hard disk (not the one with all the numbers).
    In First Aid, click on Repair Permissions.
    This only takes a minute or two.
    Background information here:
    http://docs.info.apple.com/article.html?artnum=25751
    and here:
    http://docs.info.apple.com/article.html?artnum=302672
    If you were having any serious problems with your Mac you might as well complete the exercise by repairing your hard disk as well. You cannot do this from the same start-up disk. Reboot from your install disk (holding down the C key). Once it opens, select your language, and then go to Disk Utility from the Utilities menu. Select your hard disk as before and click Repair.
    Once that is complete reboot again from your usual start-up disk.
    More useful reading here:
    Resolve startup issues and perform disk maintenance with Disk Utility and fsck
    http://support.apple.com/kb/TS1417

  • IMac gpu Heatsink reading -192, DVD fan on full blast

    Recently had a problem where my DVD fan would turn on full blast. Did SMC update through apple, smc reset, pram reset. everything. Download iStat after none of that worked, and it said my gpu heatsink was at -192 degrees F. Obviously thats not right. What could this be?

    Sounds like a faulty sensor or loose sensor cable.
    Run the Apple Hardware Test, as per > Using Apple Hardware Test

Maybe you are looking for