xb270hu half screen red vertical lines/full screen pulsing vertical lines

If the monitor is on for a few hours, the left half of the screen starts to get red vertical lines, but is only noticeable on pure black. Another few hours later, the whole screen will either freak out with random squares and lines and colors, or go black with random colored pulsing vertical lines (usually that one). If I turn the monitor off for about 30 seconds, everything goes back to normal and the process starts over.

Thoughts?