Screen suddenly turns off randomly, not controllable

Question

I am using MacOS with MacBook Pro 2016 (13-inch)

Recently, I have upgraded my laptop to High-Sierra.

After upgrading, I found that the laptop monitor randomly turns off when idling. I mean, when any human interaction (like from keyboard or mouse) is not present.

The annoying thing is that sometimes even only after 5 seconds doing nothing with keyboard or mouse, the monitor turns off itself and go to 'lock' screen.

For example, watching Youtube for about 10 seconds and monitor go black. but it's random that sometimes more than 10 minutes go nothing.

Important thing is that I have tried many options to manage this problem.

These are what I have tried:

1. turn off/on screen saver with various time settings.
2. Energy saving and changed the slide bar for many settings.
3. reset NVRAM
4. used third-party app like Owly.

Is there any other option to solve this problem? Thank you.

Answer 1

As @John Smith mentioned in the Spiff's answer, it looks like a bug of macOS which now seem to be fixed.

The problem suddenly disappeared a few months ago with macOS minor upgrades.

Nothing specific effort was managed to fix the problem. Neither magnetic matter nor third party applications was the problem.

Answer 2

Make sure you don’t have any magnets near your MacBook’s “lid closed” magnet sensor ("hall effect" sensor). You could be accidentally tricking your Mac into thinking you closed the lid and want it to sleep.

Even setting a running MacBook on top of a closed MacBook is enough to cause the running MacBook’s hall effect sensor to detect the closed MacBook’s lid magnet and go to sleep.

The last person I suggested this to realized he had a tablet stylus on his desk near his MacBook and the stylus had a magnet in it. Also watch out for magnetic clasps in watch bands and bracelets, magnetic “health” bracelets, etc.

This answer might not end up being the case for you, but I’ve seen this hit enough people that I like to post this answer anytime someone asks about MacBooks randomly sleeping or screen-blanking

Answer 3

Mine did the same. Apple "fixed" it four times and even replaced the computer without resolution of the problem. I finally discovered that it was the magnetic clasp on my Apple Watch band triggering the magnetic sensor in the upper left portion by the keyboard. This is normally triggered by a magnet in the lower left portion of the display the tells the computer when it is shut.

Answer 4

The process is, boot to recovery (⌘-R at boot, hold these keys before the Apple logo), open Terminal:

csrutil disable

Then reboot to the OS, run

sudo mount -uw /

and

sudo killall Finder

commands, then

cd /System/Library/Extensions

and

sudo mv AppleThunderboltNHI.kext AppleThunderboltNHI_kext.bak