Fix a Black Screen when the Mac is waked up from the sleep state

If the Mac repeatedly gets stuck on a black screen when waking from sleep, you should reset the onboard power management and NVRAM.

For modern MacBook Pro machines, the steps to perform both SMC and NVRAM reset are as follows:

• Turn off the Mac
• Disconnect the Power cable
• Hold down Shift + Control + Option and Power button at the same time for 12 seconds
• Release all keys at the same time, then reconnect the Power cable and turn the Mac back on again
• Next, reboot the Mac again and this time hold down Command+Option+P+R keys concurrently for about 20 seconds, this resets the NVRAM