Apple 540C, 520C manual Video

	Troubleshooting		Symptom Charts/Video (Continued) - 9
		Video (Continued)
Backlight doesn’t		1	Verify that backlight cable connection is secure.
operate		2	Check cable, inverter board, interconnect board,
		3	daughterboard, and motherboard connections.
			Verify that cables are not pinched or severed.
		4	Replace inverter board.
		5	Replace interconnect-to-inverter cable.
		6	Replace interconnect board.
		7	Replace interconnect-to-display cable.
		8	Replace display.
		9	Replace daughterboard.
		10	Replace motherboard.
Thin white line is		PowerBook 520/520c: Thin white line is normal.
always on at middle of
screen