Hello... there are seperate PCB cards in my TV... Power Supply, Inverter, Display/LCD, Connector interface, Main... ETC. I have found parts avaiable on the BAY for my TV repair. Alot of units are parted out due to LCD damage during Shipping.
The Inverter board and Power Supply boards are my suspects here... they both power up the Light Tubes.
Have you opened up your Monitor yet to get a better idea of what PCB's you have in it? or tried their site for similar problems or repair parts?
Also check the simple " reconnect " all plug connections in it? and look for loose or bad solder joints on the PCB's?