1. Check if the 15pin RGB D-connector is connected to the lighting console. Also check if the connection is lose.
   
2. Check if the power cord to the Monitor is lose or disconnected.
3. Check if the switch on the Monitor is switched ON
   
4. Check if the Switched Socket Outlet is turned on.
   
5. Check to see if there is any Power coming from the switch socket outlet. (Danger: If you are not trained or qualified please get an electrician to check for you).
   
6. If there is no power from the Switch socket Outlet, the MCB breaker  might have tripped. (Danger: If you are not trained or qualified please get an electrician to check for you).
7. Replace the Monitor with a working unit,  Change the Monitor together the mains power cord and RGB cable. There could be problems in the Monitor or Power Cord or Plug or RGB cable.