Help! I woke my computer from rest yesterday to these lines on my screen. It's also flickering. I'm seeing it could be the LCD or maybe graphics card? I'm in Korea and don't have an Apple Store nearby, so I thought I'd start here and see if anyone can shed some light.
iMac 27-Inch (late 2015)
Model A1419
iMac 27-Inch (late 2015)
Model A1419