Published by admin
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”.
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.
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.
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.
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.