I have a new iMAC (2 months old). When I scroll up or down I get a gross looking distortion on the screen about 1/3 of the way from the top of screen.
The display is set at Apple's default screen resolution of 1920 x 1080 pixels. The distortion is probably about 5% of the vertical number of pixels; hence, around 50 lines thick!
The display is set at Apple's default screen resolution of 1920 x 1080 pixels. The distortion is probably about 5% of the vertical number of pixels; hence, around 50 lines thick!