Sometimes a MacBook Pro user experience is marred by a system freezing during waking up from the Sleep Mode. The screen remains black, although you can see a mouse pointer on it and the backlight. It can also happen when a user has already entered his or her credentials on the sign in screen. A problem is usually more likely to appear when a computer is connected to a power source.
The first thing you need to try is upgrading to the latest version of macOS if you have not done it yet. If things stay the same, consider the following options.
A Safe Mode Boot
It is reasonable to let the system perform necessary checks and clear the caches. In order to enter Safe Mode:
- After starting a Mac, instantly press and keep holding the Shift
- Release the Shift button when a sign in window appears. In case you’re using FileVault to encrypt your startup disk, the system will ask you to enter your name and password.
- Then restart your Apple computer as usual, put it in Sleep Mode and see if there are freezing issues when a computer wakes up.
Running First Aid Disk Utility
This tool may help in isolating the problem if the cause of the problem is hard drive related. If you find an error, inform Apple support about it. You can find First Aid either via Spotlight, or Finder. Just type Disk Utility in Spotlight, open it and select First Aid tab. Or, go to Finder, choose Applications and then click Disk Utility.
Resetting the PRAM/NVRAM
If the previous step did not lead to success, try resetting the Parameter RAM (PRAM) or Non-Volatile Random-Access Memory (NVRAM) if you own a newer MacBook Pro. It is a small volume of memory used for storing certain settings like display resolution, sound strength, etc. Its resetting may be really helpful in this situation.
Important: Turn off the firmware password if you use it before resetting the PRAM/NVRAM. Otherwise, a Mac may start up from macOS Recovery.
- Make sure you have unplugged all external hardware.
- Shut a Mac down.
- Press the power button and immediately press and hold Opt-Cmd-P-R keys together. Do it for around 20 seconds, during which a Mac will restart.
Resetting the SMC
The System Management Controller (SMC) is responsible for low-level functions like battery management, keyboard backlighting and so on. It can also cause problems with waking up from the Sleep Mode. To reset it:
- Shut down a Mac.
- Simultaneously press Shift-Ctrl-Option keys on the keyboard and a power Release them after 10 seconds.
- Turn on a Mac again by pressing a power
Note: Keep the power cable plugged in during the process.
Replacing SATA Cables
This may look like an unusual solution, but some users report that their problems with MacBooks Pro freezing while waking up from sleep are gone thanks to replacing a SATA cable. It can be defective or worn out and thus, unable to transfer data properly.
Back up all your data and contact an Apple Store or Authorized Service Provider if the problem seems to be unmanageable.