Screen Flicker (late 2013 15" rMBP)

[skottichan]

So, it's a little over a year since I bought my current MBP.

Recently, it's developed a quirk where when I have either my Cintiq or another external monitor plugged in, I get these random blocks of quick bursts of static or colors on either the MBP's display or the external (sometimes even on both).

This happens via the HDMI as well as the DP ports, I'm curious, is this a harmless bug or a sign of something bigger?

 

[Samuelsan2001]

It's your graphics card switching because it will only use the dGPU on the external screen,there seems to be a glitch in El Capitan causing this artefact.