I don't know if it's the same as the head unit in my Camry or not, but in it, the backlight for the LCD display is supplied by a grain-of-rice sized light bulb. Mine burnt out; found a replacement bulb at Radio Shack. It wasn't too difficult to replace. The bulb's two wires are soldered to pads on the circuit board.
1992 Camry LE, V6 (3VZ-FE), ABS brakes, dark emerald pearl, owned since new. Replaced HGs @332k, now at 354k
1996 Avalon XLS, ABS brakes, super white II, acquired w/ 139k, now at 292k
2001 Yamaha FZ1, Ivan's jet kit, resprung, Ohlins rear shock, Race Tech cartridge emulators in forks, 48k miles