system management controller(SMC)
The SMC (system management controller) is a chip on Intel-based Macs that manages important physical components of your computer. The SMC controls various hardware functions like cooling fans, status lights, system performance, and power supply — unlike the PRAM, which deals more with operating system software
How to perform SMC Reset on MacBook?
Here’s how to reset the SMC on notebooks with non-removable batteries:
- Shut down your Mac.
- Press and hold Shift, Control, and Option on the left side of the keyboard. At the same time, press the power button.
- Hold for 10 seconds.
- Release the keys and then turn on your Mac
What the SMC does is this:
On Intel-based Mac computers, the SMC is in charge of these and other low-level functions:
- Responding to the power button’s push
- Responding to the opening and closing of the display lid on Mac laptops
- Management of the battery
- Controlling the temperature
- Sensor for Sudden Motion (SMS)
- Sensing of ambient light
- Backlighting on the keyboard
- Management of the status indicator light (SIL)
- The battery status indicator is illuminated.
- For some iMac screens, choosing an external (rather than internal) video source
- How to tell if the SMC needs to be reset:
- These signs and symptoms may indicate that an SMC reset is required:
- Even if your computer isn’t in use and is properly ventilated, the fans on it run at a high speed.
- The backlight on the keyboard is malfunctioning.
- If there is a status indicator light, it behaves wrongly.
- On Mac notebooks with a non-removable battery, the battery indicator LEDs, if present, function erroneously.
- When you push the power button on your Mac, nothing happens.
- When you close or open the lid on your Mac notebook, it does not respond properly.
- The battery isn’t charging correctly.
- You can’t turn your Mac back on if it sleeps or shuts down unexpectedly.
- The display backlight does not adjust to variations in ambient light.
- The built-in USB-C port on your MacBook or MacBook Pro does not charge.
- External devices attached to the built-in USB-C connector on your MacBook or MacBook Pro are not recognised.
- If present, the MagSafe power adapter LED does not show proper charging activity.
- Even though your Mac’s CPU isn’t under any especially heavy demand, it runs slowly.
- A Mac that supports target display mode does not switch into or out of target display mode as expected, or at inopportune moments.
- When you move a Mac Pro (late 2013), the lights around the I/O ports does not turn on.