Take the computer out of the monitor troubleshooting equation.
* Turn the monitor off
* Disconnect all monitor cords from the computer
* Disconnect the monitor power cord from the rear of the monitor
* Press and hold the monitor power button in for 5 seconds
* Reconnect the monitor power cord to the rear of the monitor
* Turn the monitor on
* The floating red/green/blue/white dialog box should appear on screen against a black background. What do you see?

Nothing. It keeps blinking. Is it  defective? Can you tell me what actually went wrong? Thanks

I cannot since it could be one of several internal components. We do not repair them, all we do is replace them under warranty.

I have experienced exactly the same problem as this. My monitor is about 5 years and will not switch on or off and the screen reamins blank. All that happnes is the LED flashes green. I ahve tried the correction you describe and it does not work. Is this a common probel with monitors this age?

Any other suggestions as to what may be wrong or another self try fix?

John