On these, it could be poor earthing of the inverter pcb via the 3 mounting screws nearest centre of panel.
Remove pcb and polish the copper screw pads on both sides of the pcb as well as the metal around the
screw holes. You could also add an earthing link from one of the copper pads to the metal chassis. If that fails, you'll have to open the display panel to the point where you can observe the ccfl
backlights but still operate the tv. In that 2 second window of backlight operation, you'll be able to see if any
of the ccfl-s are failing to ignite or have a pinky glow. May have to start it a few times to identify the faulty
one/s.Sharp are notorious for bad lamps.