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Weird horizontal line on MacBook Pro '16 2019

Hello,

I have a problem with a strange horizontal line on the display. It is very rare, and sometimes it can appear twice a day. The line appears only when using command + tab, but as I wrote before - not every time, but sometimes.


It looks like image bellow (its really hard to do screenshot when lane appears just for 1 sec, so I found that picture on apple discussion forum).

MacBook Pro 16″, macOS 11.2

Posted on Apr 4, 2021 8:55 AM

Reply
Question marked as Top-ranking reply

Posted on Apr 4, 2021 9:55 AM

dorian29 wrote:

Hello,
I have a problem with a strange horizontal line on the display. It is very rare, and sometimes it can appear twice a day.

The line appears only when using command + tab, but as I wrote before - not every time, but sometimes.

It looks like image bellow (its really hard to do screenshot when lane appears just for 1 sec, so I found that picture on apple discussion forum).

MacBook Pro 16″, macOS 11.2



Your screenshot shows a boot up sequence—


how does this square with your statement "The line appears only when using command + tab" ?

I see now your explanation—found image. Ok



Is this pixelated fault in the exact location as you see the HUD (Heads Up Display) when you Command Tab ?


Verify your software is up to date:

sw_vers


ProductName: macOS

ProductVersion: 11.2.3

BuildVersion: 20D91




To trouble shoot further you can:


—Try a SafeBoot https://support.apple.com/en-us/HT201262

Takes noticeable longer to get to the login screen, does a 5-15 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc.

Login and test. Reboot as normal and test as caches get rebuilt.


In Safe mode third party system modifications and system accelerations are disabled, it removes malware, etc hampering smooth operation, however a reboot will put it back to normal mode.


This test will tell you if third party interference; extensions etc are not loaded in safe boot mode.



—Test issue in another user (or guest user) account https://support.apple.com/guide/mac-help/set-up-other-users-on-your-mac-mtusr001/mac

This will tell you if it a universal issue or isolated to your user/admin account. 



Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus




1 reply
Question marked as Top-ranking reply

Apr 4, 2021 9:55 AM in response to dorian29

dorian29 wrote:

Hello,
I have a problem with a strange horizontal line on the display. It is very rare, and sometimes it can appear twice a day.

The line appears only when using command + tab, but as I wrote before - not every time, but sometimes.

It looks like image bellow (its really hard to do screenshot when lane appears just for 1 sec, so I found that picture on apple discussion forum).

MacBook Pro 16″, macOS 11.2



Your screenshot shows a boot up sequence—


how does this square with your statement "The line appears only when using command + tab" ?

I see now your explanation—found image. Ok



Is this pixelated fault in the exact location as you see the HUD (Heads Up Display) when you Command Tab ?


Verify your software is up to date:

sw_vers


ProductName: macOS

ProductVersion: 11.2.3

BuildVersion: 20D91




To trouble shoot further you can:


—Try a SafeBoot https://support.apple.com/en-us/HT201262

Takes noticeable longer to get to the login screen, does a 5-15 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc.

Login and test. Reboot as normal and test as caches get rebuilt.


In Safe mode third party system modifications and system accelerations are disabled, it removes malware, etc hampering smooth operation, however a reboot will put it back to normal mode.


This test will tell you if third party interference; extensions etc are not loaded in safe boot mode.



—Test issue in another user (or guest user) account https://support.apple.com/guide/mac-help/set-up-other-users-on-your-mac-mtusr001/mac

This will tell you if it a universal issue or isolated to your user/admin account. 



Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus




Weird horizontal line on MacBook Pro '16 2019

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