The issue seems to arise because of a cable that is used to connect the MacBook’s display to a control board in the base of the computer, iFixit explains. Starting with the 2016 MacBook Pro, Apple has used a pair of flexible ribbon cables that are pulled tight every time you open the lid on the computer. That may be damaging them over time.

As the cable breaks down, it can cause an odd “stage light” effect at the bottom of the display when…