MacBook 2015 - The screen is flickering with horizontal lines

Hello everyone!

I have an issue (see below) on the screen if anyone could help me with the solution or at least with the diagnostic – I thank you in advance!

MacBook (Retina, 12-inch, Early 2015)

Processor 1,2 GHz Dual-Core Intel Core M

Memory 8 GB 1600 MHz DDR3

Graphics Intel HD Graphics 5300 1536 MB

Model A1534

Issue:

The screen is flickering with horizontal lines.

On the black appears blue Lines and on the white appers yellow lines (check attached photos).

The issue occurs even using the power outlet or using the battery.

Actions to try to fix:

·      PRAM and SMC reset (several times);

·      Diagnostic mode does not show any problem;

·      macOS reinstallation.

Findings:

·      In safe mode the issue does not occurs (Why?);

·      If a second display (VGA) or TV (HDMI) is plugged (using the single USB-C port) the issue does not occurs too (Why?).

Any tips will be welcome.

Thank you!!!