Brother HL-5040

HL-5030/5040/5050/5070N SERVICE MANUAL
3-23
2.3 Sensors
2.3.1 Cover sensors
Detect opening and closing of the front cover.
Fig. 3-35
2.3.2 Toner sensors
Detects if there is toner in the toner cartridge. The toner sensor at the left side emits light
through the window on the left side of the toner cartridge, then the toner sensor at the right
side receives it when the toner is low. They also detect whether or not the drum unit is
installed. (The toner cartridge is installed in the drum unit.)
Fig. 3-36
Toner sensor
(Light emission)
Toner sensor
(Light reception)
Front cover sensor