Black screen flashes after initial power up

Possibly the backlights have failed. The screen part may be working normally. Get a bright light close to the front of the screen, see correct image faintly. Commonly it is failure of the high voltage inverter circuits that power the backlight fluorescent lamps. You can probably buy replacement circuit or repair the one you have. I have done this on another model. You need to search the web for experience of the same model. RDL.