The SMC (System Management Controller) is a chip in Intel MacBooks that manages, among other things, power, charging, the battery, the fans and the keyboard backlight. If it gets confused, your MacBook can behave strangely: it does not charge, the fan keeps running, or it will not turn on. An SMC reset puts that chip back to its starting state. This article explains when an SMC reset helps and how to do it, per type of MacBook.
Blue Apple repairs MacBooks in Amsterdam. An SMC reset is a safe first step, but if the problem comes back, there is often more behind it; more about that at the end.
When does an SMC reset help?
- The MacBook does not charge, or the light on the MagSafe plug does nothing.
- The fan runs loudly while the Mac is not warm or idle.
- The MacBook will not turn on, or shuts off by itself.
- The keyboard backlight or brightness does not respond properly.
- The MacBook does not sleep when you close it.
A Mac with an Apple chip: no SMC reset needed
Macs with an Apple chip (M1 and newer, and the MacBook Neo) have no separate SMC. The functions are in the chip itself. The equivalent of an SMC reset is: shut the Mac down, wait half a minute and turn it on again. For a charging problem, connect the charger and wait a few minutes.
Intel MacBook with T2 chip (about 2018 to 2020)
- Shut the Mac down.
- Hold the left Control, the left Option and the right Shift for seven seconds.
- Keep holding them and also press the power button. Hold all four for seven seconds. (The Mac may turn on and off again.)
- Release, wait a few seconds and turn the Mac on.
Intel MacBook without T2 with a non-removable battery (about 2009 to 2017)
- Shut the Mac down.
- Hold the left Shift, Control and Option, and press the power button at the same time.
- Hold all four for ten seconds.
- Release and turn the Mac on.
Very old MacBook with a removable battery
Remove the charger and the battery, hold the power button for five seconds, put the battery back and turn the Mac on.
Which type do I have?
Check About This Mac. If it shows a chip such as M1 or newer, you need no SMC reset. If it says Intel, look in System Information, Controller: if it says "Apple T2", use the T2 method. Also see which MacBook do I have.
After the reset
Settings such as brightness and keyboard backlight may return to default. Your files stay; an SMC reset erases nothing.
The problem comes back
If the reset does not help, or the problem returns after a few days, it is probably a hardware problem: a worn battery, a faulty charging port, a dirty or broken fan, or a problem on the logic board. Also read MacBook says "Not charging" and MacBook runs hot or slow.
What we do at Blue Apple in Amsterdam
We measure the power, test the battery, the charging port and the fan, and find where on the logic board the problem is. You hear beforehand what is needed and what it costs. More on our pages about MacBook will not turn on and MacBook battery replacement.
Frequently asked questions
Is an SMC reset dangerous?
No. Nothing is lost, only a few settings return to default.
Should I also reset the NVRAM?
Only for other problems, such as the startup disk or resolution. That is a separate reset.
How often may I reset the SMC?
As often as needed, but if you have to do it again and again, have the MacBook checked.
