If your Mac or Macbook computer’s fans have been running at high speeds even though you’re not running many applications and your machine is properly ventilated, you can run this quick troubleshooting step.
Resetting the System Management Controller (SMC):
By resetting the SMC we can correct or eliminate reasons why you are experiencing this fault.
Please follow these steps:
Reset on an iMac:
1. First you need to shut down your Mac, only once this is done can you move to the next step.
2. Unplug the Mac’s power cable from the back of the Mac.
3. Wait 15 seconds before re attaching the power cable.
4. Now wait a further 5 seconds before turning the Mac back on.
Reset a Macbook / Macbook Pro:
Caution is advised when removing the battery on a Macbook as part of resetting the SMC as this can be hot from being used. Wait for it to cool down before you proceed.
Only some models of Mac portables are desgined for the users to remove the batteries. These are the current models that you can remove batteries for:
MacBook (13-inch, Mid 2009)
MacBook (13-inch, Early 2009)
MacBook (13-inch, Late 2008)
MacBook (13-inch, Early 2008)
MacBook (13-inch Late 2007)
MacBook (13-inch Mid 2007)
MacBook (13-inch Late 2006)
MacBook Pro (15-inch, Late 2008)
MacBook Pro (15-inch Early 2008),
MacBook Pro (17-inch, Late 2008), and earlier
1. Shut down the Mac before you start.
2. Disconnect the power adapter (if you have this connected).
3. Remove the battery.
4. Once the battery is removed press and hold the power button for 5 seconds.
5. After 5 seconds release the power button and reinstall the battery into the Mac.
6. Reconnect the power adapter and turn the Mac back on.
If, after resetting the SMC, the problem hasn’t resolved it is recommended that you send your machine to an Apple Authorized Repair Centre.