Has your Mac been on a whim lately? For example, are the fans always running at full power, the keyboard backlight not working, or the battery not charging properly? You could solve the problem with an SMC reset.
The SMC on Macs is responsible for numerous low-level functions. It deals with the management of the battery and dissipation, the response to the pressure of the power button and the opening and closing of the MacBook lid, the motion sensor (SMS) and the ambient light detection sensor, the keyboard backlight, the battery status indicator and the selection of an external video source.
If you have a problem with any of these functions, resetting the SMC may fix it. But not only that, if you notice that your Mac is very slow even when not very heavy apps are running, a reset of the SMC could be very useful.
In the following paragraphs, I will explain in as much detail as possible, how to reset the SMC of the Mac. The procedure to be carried out varies according to the model of Mac in your possession, therefore, before proceeding I recommend that you read the entire article carefully.
When to perform an SMC reset
The following symptoms may indicate that the SMC needs to be reset:
- Mac fans always run at full speed.
- The headboard backlight does not work well.
- The status indicator behaves incorrectly.
- The battery lights are not working well.
- The external light sensor is not responding.
- The battery does not charge or charges slowly.
- The power button does not respond.
- After the Stop, it is no longer possible to start macOS.
- Mac suddenly shuts down or won’t shut down.
- macOS freezes or runs slowly.
- The response to closing or opening the lid does not work properly.
- Charging via USB-C port does not work.
- Mac does not recognize external devices connected to the USB-C port.
- The LED on the MagSafe connector is not working.
Preliminary operations
If you have one of the problems described above, the SMC reset may solve the problem, First, I suggest you perform the following procedure.
- Turn off the Mac, to do so click on the Apple icon, present at the top left and then click on “Turn off” . If your Mac is frozen, try to force quit apps using the keyboard shortcut CMD + ALT + ESC. If the keyboard does not respond, forcefully shut down the Mac by holding down the access key;
- After turning off the Mac, press and hold the power button for 10 seconds;
- Release the power button and wait another 10 seconds;
- Turn on the Mac normally.
If after following this procedure the issues are not resolved, reset the SMC.
How to reset the SMC
As previously written, the steps to take to reset the SMC vary slightly depending on the model of Mac you have. There are four procedures, each of which is dedicated to a specific type of Mac: MacBook with T2 security chip, MacBook without T2 security chip, desktop Mac (iMac, iMac Pro, Mac Pro, Mac mini), and MacBook with battery removable.
If you have a desktop Mac, you can easily read the dedicated chapter below, if you have a MacBook, first you need to check whether or not it has a removable battery (MacBooks produced after 2009 have no battery removable), to do so just turn the Mac over and check if the battery compartment is present. Next you need to check if your Mac has T2 security chip or not.
The MacBook in 2018 and later models have T2 security chip . If you don’t know the exact model you have, you can check for the security chip as follows:
- Click on the Apple icon, present at the top left (the apple-shaped one)
- Press the ALT key and then click on “System Information” ;
- In the window that opens, from the left sidebar, select the item “Controller” or “iBridge” ;
- If your MacBook has a security chip, you will see “Apple T2 chip” on the right side of the window.
SMC reset on MacBook with T2 security chip
If your MacBook has the T2 security chip, the steps to reset the SMC are as follows:
- Turn off the Mac;
- Hold down the CTRL + ALT + SHIFT keys (all on the right side of the keyboard) for 7 seconds;
- After 7 seconds, continuing to hold down the key combination seen above, press and hold the access key for another 7 seconds;
- Release the keys, then wait a few seconds and turn on your Mac normally.
SMC reset on MacBook without T2 security chip
On MacBooks without the T2 security chip, the SMC reset must be performed using the following procedure:
- Turn off the Mac;
- Hold down the CTRL + ALT + SHIFT + access key (all on the left side of the keyboard) for 10 seconds;
- After 10 seconds, release the keys and wait a few more seconds;
- Turn on the Mac normally.
SMC reset on MacBook with removable battery
If you have a MacBook with a removable battery, the steps to reset the SMC are as follows:
- Turn off the Mac;
- Remove the battery,
- Press and hold the access button for 5 seconds;
- Insert the battery;
- Turn on the Mac normally.
SMC recovery on desktop Mac
If you have an iMac, Mac Pro, or Mac mini, you can reset the SMC like this:
- Turn off the Mac;
- Unplug the power cord;
- Wait 15 seconds, then plug the power cord back in;
- Wait 5 seconds;
- Turn on the Mac normally.
