How does my MacBook power up?

September 10, 2017
Macbook logic board

Apple MacBooks are the most sought after laptop products because of their hardware build quality and optimised dedicated macOS. They are very reliable products that can give you years of loyal service. However, MacBooks sometimes do face issues. Understand the principle of how your MacBook works will help you to look after your beloved Macbook.

MacBook is made of these components: MacBook screen, keyboard, touchpad, case. Inside the case there is a battery, an HDD drive or SSD drive, a Wifi card, a supper drive ( for old model), and the high-tech logic board. It is the logic board combined with the macOS makes the Apple computers unique to the Windows-based PCs.

  • Once you connect MagSafe to the MacBook, the System Management Controller (SMC) on the logic board will talk to the chip on the MagSafe and the green light turns on.
  • The charging circuit receives power from Magsafe and starts charging the battery if it is not fully charged and the orange light turns on.
  • Once you press the power button of your MacBook. The button will send an electronic pulse to the SMC. After that, the system’s power management circuit will create several different power rails in the strictly pre-defined order.
  • The memory module (RAM) of a MacBook will receive power first, followed by the CPU, hard drive, DVD drive, and graphics chip.
  • SMC will validate all the power rails on the logic board. If everything is fine, SMC will send a “reset” signal to the CPU.
  • Upon receiving the reset signal, the CPU of the logic board will read and execute the BIOS/EFI codes and performs a Power-On-Self-Test (POST). The BIOS/EFI is a collection of hardware-specific codes stored in a read-only chip on the logic board. All MacBook models have their own unique BIOS/EFI. The MacBook’s macOS talks to BIOS/EFI and the BIOS/EFI talks to the specific hardware, in turn. So the macOS can be run on different MacBook models.
  • MacBook will chime and display the Apple logo. Apple’s macOS operating software will then commence loading.
  • Enjoy using your MacBook and stay away from Mac’s arch-enemy: your DRINK

If you need the help of your Macs, Contact us today on (03) 9563 8588 to find out how we can help you.

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