Monitor malfunction

My monitor alternates between on and off non-stop. This occurs when the computer is turned on and the monitor is activated (green LED on monitor). It also occurs when the computer is not powered on and the monitor’s “on” button is pressed. I’ve tried turning off the monitors main “power” button, unplugging the monitor and also disconnecting the monitor from the computer. So basically it’s happening when plugged in and the front panel “on” button is pressed. It will stop when the “on” button is pressed again and the LED turns orange.