What is the SMC of a Mac
SMC is the acronym for System Management Controller which in Castilian means System management controller. In short, we are talking about a chip that can be found on the motherboard of all Macs that include an Intel brand processor. As its name suggests, it has the necessary functions to be able to control all the processes that are interconnected between various internal components. That is, all those low-level processes are the ones that will be under the control of the SMC and they are not limited solely to the control you can have through the processor or simply through the operating system.
Its main functions include, for example, the management of the battery, the temperature, the detection of ambient light, the backlighting of the keyboard or the response of the opening and closing of a screen among many other functions. That is why this is a vital component in managing all the resources that a Mac has and although it may seem insignificant, it is not possible to have a correct operation of this chip in the event that this component does not work correctly. Specifically on the Apple website they detail the following functions.
- Power, including start button.
- Battery and charging.
- Fans and thermal management.
- Indicators or sensors for example status lights.
- Behavior when opening and closing the lid of a laptop.
Typical problems that this function solves
As we have mentioned, there are many functions that the SMC itself encompasses when it comes to coordinating different components and various functions. That is why it is vital to reset it as soon as you can find some common problems that may be related to this simple chip. The website itself indicates in detail all the problems that can occur when this chip enters a loop and surely some of these problems are familiar to you. That is why when you have any of the problems listed below, it is necessary reset the SMC as soon as possible avoiding having to restore the operating system which is undoubtedly something totally radical when a problem arises. The most common situations are the following:
- The fans speed up quickly for no reason.
- The keyboard backlight does not work properly by not adapting to changes in ambient light.
- The computer does not turn on when the power button is pressed or unexpected shutdowns occur without any explanation.
- The computer runs slowly even if they do not consume a lot of CPU resources.
- The battery is not recharging properly or is discharging quickly.
- The temperature or battery sensors do not work perfectly.
Resetting the SMC
When it is already accepted that the SMC reset must be performed due to the problems that the computer has, it is necessary to proceed to the steps to follow. In this case you have to make several distinctions between a MacBook and an iMac as well as the type of security chip that is included and the type of processor. Below you will see all the steps you must follow taking these considerations into account.
On a MacBook with a removable battery and a T1 chip
When we talk about MacBook with removable battery we have to move to models that are really old. Specifically we go to the models of MacBook Pro and MacBook released in early 2009 or earlier as well as the 13-inch MacBook from mid-2009. If you have one of these models and need to reset the SMC you will need to follow these steps:
- Shut down the Mac.
- Remove the battery carefully.
- Press and hold the power button for 5 seconds.
- Reinstall the battery in its correct place.
- Press the power button and go back to using your Mac normally now with the SMC reset.
On MacBooks with non-removable batteries and T1 chip
If you have a much more modern MacBook with a T1 chip, the process is different. Specifically, we are talking about the MacBook Pro models that were introduced in mid-2009 until 2017, the MacBook Air released in 2017 or earlier, as well as the MacBook. Once you have taken this consideration into account the steps to reset the SMC, the following steps should be followed:
- Shut down the Mac.
- On the integrated keyboard, press and hold Left Shift, Left Control, and Left Option keys.
- In addition to these three keys, you must press the fourth power button.
- Keep all four keys pressed for 10 seconds.
- Release all keys and turn your Mac back on.
On a MacBook with a T2 chip
In the case that your MacBook has a T2 chip, there are no differences in the type of battery since they are all integrated into the body of the device without the possibility of removing them. In this case the steps to be followed are the following at first:
- Shut down the Mac.
- Press and hold the power button for 10 seconds and release it.
- Wait a few seconds and turn it on again.
For a few minutes it is necessary that you test at all times if you have finished solving this problem. In the event that this is not the case, you must choose to follow the following steps:
- Shut down the Mac.
- On the keyboard, press and hold Left Control, Left Option, and Right Shift keys.
- Hold down these keys for 7 seconds and then simultaneously press the power button.
- Keep all four keys pressed for a further 7 seconds.
- Release them and after a few seconds turn the Mac back on.
On an iMac with a T1 and T2 chip
In the case of iMac, no distinction is made between the type of security chip that is integrated. In both cases, it is done in the same way and without having to press many keys at the same time. since the iMac do not have any keyboard integrated in the body unlike the MacBook that if a combination of keys can be made to have a mechanical access to the components of the device. In order to reset the SMC in an iMac, the following steps must be followed.
- Turn off your Mac and unplug the power cord.
- Wait 15 seconds and plug the power cord back in.
- Wait 5 seconds and press the power button to turn on the Mac.
Can it be reset on a Mac with a class ‘M’ chip?
As we have previously discussed, all these steps that have been discussed are for those Macs that have an Intel processor. As of 2020, Apple began to withdraw this type of processors, opting for proprietary chips from the ‘M’ range. But this was not the only difference with respect to Intel processors since the absence of an SMC chip in these devices also stood out. This is because all the functions that we have previously discussed are integrated into the same Apple chip without the need for an external component such as the SMC. This is something that also happens on the iPhone or iPad itself that integrates proprietary processors.
This does not mean that different modifications can be made since you can always use a command in Terminal called ‘pmset’ to change different settings. But the only thing that cannot be done is to restart the controller in any way. This means that when you have any of the problems that have been mentioned above, you cannot restart as in Intel, causing you to have to reset the system or restore more specifically the firmware.