820-01814 A1990 Potential Gmux Issue

[EsteTron]

A1990. External display works normally when eDP is unplugged. With eDP connected looks like this. Potential gmux issue? No signs of screen damage. Have yet to work on this model yet.

 

[EsteTron]

Looks like this one still has Apple Care on it. Going to have customer contact Apple. But still curious what the issue is. I believe I saw Rossmann do a video where the eDP connector had debris on the backlight and data line that killed the GMUX.

 

[dukefawks]

GPU issue, certainly take to Apple if it does not have liquid damage.

 

[EsteTron]

Thanks Duke. The only reason I didn't suspect GPU is because with the eDP cable unplugged, using an external monitor, there were no graphical anomalies. Thankfully, this one still has a warranty until 2022.