1 .Start up in safe mode
To start up in safe mode:
- Start or restart your Mac, then immediately press and hold the Shift key. The Apple logo appears on your display. If you don’t see the Apple logo, learn what to do.
- Release the Shift key when you see the login window. If your startup disk is encrypted with FileVault, you might be asked to log in twice: once to unlock the startup disk, and again to log in to the Finder.
To leave safe mode, restart your Mac without pressing any keys during startup.
2. 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
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
3.How to reset the SMC on Mac notebooks
If you have a MacBook Pro (2018), skip ahead to the section that deals with your Mac.
To reset the SMC on a Mac notebook, first determine whether the battery is removable. Most older Mac notebooks have removable batteries. Mac notebooks that have nonremovable batteries include MacBook Pro (Early 2009 and later), all models of MacBook Air, MacBook (Late 2009), and MacBook (Retina, 12-inch, Early 2015 and later). Learn more about Mac notebook batteries.
If the battery is nonremovable:
- Choose Apple menu > Shut Down.
- After your Mac shuts down, press Shift-Control-Option on the left side of the built-in keyboard, then press the power button at the same time. Hold these keys and the power button for 10 seconds. If you have a MacBook Pro with Touch ID, the Touch ID button is also the power button.
- Release all keys.
- Press the power button again to turn on your Mac.
4.And also didn’t work, & what i did is this:
i open up the mac cover
1. remove the battery cables
2. i remove NVME hard drive see video carefully
3.I connect again all connectors
4.put the Nvme drive again
5.Turn On MacBookPro
and as you see at the video it will Open up and now is working ok and no problem.
Screwdriver suggestions for you MacBook Pro and Air:
1. iFixit Pro Tech Toolkit – Electronics, Smartphone, Computer & Tablet Repair KitScrewdriver Toolkit
2. iRepairmac Bottom Case Screw Set and Pentalobe Screwdriver for MacBook Retina 13″Screwdriver P5