Before we look at the monitor as the culprit, hook a spare monitor to the computer to make sure it is not a video graphics card causing the problem, once this is ruled out we can look at the AOC assuming the computer has checked out. Detach the video cord from the computer and the monitor (If possible) and sub another cord in it's place so we can rule it out. If you have gone this far and still no change, then the AOC monitor is the issue, the video is processed on the main board that is attached behind the LCD panel display and would be bad news, unless you are lucky enough to find a bad solder connection on that board, your choice is going to be very limited in what you can do. The monitor will probably have to be replaced at this point because the cost to repair will not be justified.

Failing powerboard capacitors, capacitors not holding charge, needs repair by tv type repairman