Sounds like a voltage issue. Have you tried swapping the plugs and see if the monitor works with the other plug?
Sounds like a voltage issue. Have you tried swapping the plugs and see if the monitor works with the other plug? If so just replace the faulty plug. I would also try swapping the vga cable to rule that out also. tRY DOING A FACTORY RESET USING THE MENU BUTTONS ON THE FRONT OF THER MONITOR. Oops sorry for the caps.