Apple Macbook pro screen reset

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Posted on August 14, 2020

half of the screen when black

Reset PRAM. http://support.apple.com/kb/PH4405

Reset SMC. http://support.apple.com/kb/HT3964

Choose the method for:

“Resetting SMC on portables with a battery you should not remove on your own”.

Reset NVRAM or PRAM on your Mac

If your Mac has issues related to settings stored in NVRAM or PRAM, resetting it might help.

NVRAM (nonvolatile random-access memory) is a small amount of memory that your Mac uses to store certain settings and access them quickly. PRAM (Parameter RAM) stores similar information, and the steps for resetting NVRAM and PRAM are the same.

Settings that can be stored in NVRAM include sound volume, display resolution, startup-disk selection, time zone, and recent kernel panic information. The settings stored in NVRAM depend on your Mac and the devices that you’re using with your Mac.

If you experience issues related to these settings or others, resetting NVRAM might help. For example, if your Mac starts up from a disk other than the one selected in Startup Disk preferences, or a question mark icon briefly appears before your Mac starts up, you might need to reset NVRAM.

How to reset NVRAM press

option + command + P + R

Shut down your Mac, then turn it on and immediately press and hold these four keys together: Option, Command, P, and R. You can release the keys after about 20 seconds, during which your Mac might appear to restart.

If your Mac is using a firmware password, this key combination does nothing or causes your Mac to start up from macOS Recovery. To reset NVRAM, first turn off the firmware password.

When your Mac finishes starting up, you might want to open System Preferences and adjust any settings that were reset, such as sound volume, display resolution, startup disk selection, or time zone.

Learn more

  • If you’re using a desktop Mac instead of a notebook, and settings such as sound volume or time zone are reset every time you shut down and unplug your Mac, you might need to replace the battery inside your Mac. This small battery is on your computer’s logic board, and it helps NVRAM retain settings when your Mac is unplugged. You can take your Mac to an Apple service provider to replace the battery.
  • If you experience issues with sleep, wake, power, charging your Mac notebook battery, or other power-related symptoms, you might need to reset the SMC (System Management Controller).

alternate solution

Symptoms: you open up your late 2014 macbook pro 15” and expect it to wake from sleep in 0.5 seconds. Instead the screen stays black.

  • Press shift-option-control-power and release them all at the same time. This resets the “system management controller”, amongst others it makes sure the “power” button actually reacts.
  • Now look at the back of your mac’s screen. Make sure the light of the apple logo is off. If necessary, keep the power button pressed for 5 seconds to force a shutdown. (The power button should work again after step 1).
  • Keep your fingers ready for pressing command-option-p-r at the same time. You need both hands for this weird combination. Press the power button and then hold these four keys. Your mac will now actually boot, give you the startup sound and lo and behold, you’ve got your screen back.

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