2019 iMac with Big Sur suddenly displaying thin horizontal line on screen

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Level 1

14 points

2019 iMac with Big Sur suddenly displaying thin horizontal line on screen

Running a 2019 iMac 4K Retina Display 21.5inch with latest Big Sur version. After a month post install or so, suddenly displaying 1 thin grey/white horizontal line across the whole screen 1/2 of the way up from the bottom.

Tried re-installing BS through Recovery, ran Diagnostics (no HW fault found code ADP000). No can do.

Is this a HW problem…? or a Big Sur issue ?

See attached image of screen portion with grey line.

/Users/Francois/Desktop/Screenshot 2021-06-08 at 13.02.55.png

iMac 21.5″, macOS 11.3

Posted on Jun 8, 2021 5:05 AM

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Answer 1

Jack-19

Level 8

46,182 points

Jun 8, 2021 5:27 AM in response to fjd101

There is nothing in the screenshots, and considering that the line can be seen under the Apple logo at startup means this is a hardware issue. Please learn about repair options here: Get Support.

Cheers,

Jack

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Answer 2

Jack-19

Level 8

46,182 points

Jun 8, 2021 5:08 AM in response to fjd101

A photo would help, but you need to upload it using this tool.

Otherwise, we just see the file path on your computer.

Does the horizontal line appear outside of macOS, such as in the Recovery Mode?

Cheers,

Jack

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Answer 3

fjd101 Author

Level 1

14 points

Jun 8, 2021 5:21 AM in response to Jack-19

No, the line does not appear when starting Recovery. Only when OS is installed. Restarting the Mac the line is in evidence right from the start beneath the white apple logo. Uploading image again : line appears below the Submit button

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