My Late 2009 27-inch iMac runs its fans at full speed soon after startup. On the other hand my Mid-2007 24-inch iMac NEVER runs its fans. I want to get my 2009 iMac to stop making all the fan noise. How do i stop the fans from running continuously on my Late 2009 27-inch iMac running El Capitan?
Hi Carolyn,
I was at the Genius Bar yesterday. The diagnostics all looked heathy, no problems were found with hardware or software. The computer runs fine except for the fan problem. The Apple store will not open up this computer since it recently became "Vintage" and so no longer supported.
The Apple Authorized service providers cannot offer me a confident answer to the question "can they fix it?" They can certainly run diagnostics, but that was already done at the apple store and no problems were found.
I can open up the computer, I have dusted it with compressed air. Doesn't help. I would like to try disconnecting the fans somehow.
Mark
The logic board or some other internal component is failing and would have to be replaced if you want to keep using the machine. Apple would probably decline to service it because of its age. An independent authorized service provider might be willing, but the part may no longer be available, and if it is, the cost of the service may be more than it's worth to you.
I have exactly your problem but I can't understand how you fixed it
Thanks Linc,
This problem begins as soon as I turn my mac on before I load any apps. By the time the desktop appears the fans are running full out and never stop or go any slower ever. It is very noisy as you might imagine.
Mark
Hi Linc,
A little back history.. about six months ago I had the logic board replaced and the computer runs fine now except for the fans. In fact the fan problem began after the logic board was replaced and is currently the only problem with the computer. I would like to cut the wires to the fans if that will not somehow cause a hardware alarm that will make the computer unusable. I know the fans are not necessary, my 2007 iMac never runs its fans at least not audibly.
Mark
The fan is necessary. It runs all the time at minimum speed, which is usually not audible. If one of the temperature sensors on the logic board isn't working, the fan will overrun and be noisy. If you disable the fan, the machine either won't run at all or it will quickly overheat and shut down.
The best you can hope for is that the sensor for the hard drive wasn't connected when the LB was replaced, or that it has come loose. That would be fairly easy to fix.
Line,
Thanks again for you input. I will continue my search for the problem. When I opened up my iMac last time I noticed that the hard drive heat sensor wire was buried underneath the hard drive, when it should have been tucked to the side instead. I am wondering if the wire could have been damaged or shorted out by being forced under the drive. I will take the hard drive out next time, pull the wires out from under it and look to see if the wires are ok and not shorting out.
Thanks again,
Mark
For about a year I've been having a random problem of excessive fan speed on my Late 2012 iMac 21.5". Suddenly the fan will ramp up for no apparent reason. The system temperatures are never high. Checking Activity Monitor doesn't provide any clue. Resetting the SMC does not correct the behavior. Eventually the fan ramps down on its own. But tonight it ramped up and stayed up through sleep, restart, & shut down (and SMC reset). A lot of air was being forced out of the grill on the rear, and the noise was annoying. Feeling frustrated, I used my fingers to give a sharp rap to the screen near the top edge. The fan immediately ramped down to normal! And it has stayed in the normal range. The noise is inaudible. I'll be the first to agree that this is comical.
It's not possible to completely stop the fans. Your iMac would over heat.
But what you can do is Reset the System Management Controller (SMC) on your Mac - Apple Support
If you've already done as recommended in the support article, please see below.
Apps can affect Mac performance, battery runtime, temperature, and fan activity - Apple Support
HI Carolyn,
Thank you for your speedy reply. The SMC reset does not fix my fan problem unfortunately.
Mark
Yes I have read the posting on fan problems and I tried this approach to no avail.
How do I stop the fans on my iMac?
