Canon LBP3010 Series, Service Manual, Page: 53 / 146

Chapter 2
2-21
The engine controller detects the position of the Toner cartridge detection flag to judge the absence/presence of the Toner cartridge.
At the time of turning on the power or closing the upper cover, the engine controller judges the position of the Toner cartridge flag based on the output result of the
leading edge sensor (PS801).
When the output result of PS801 is L, it is judged that the Toner cartridge is absent; If being H, it is judged that the Toner cartridge is present.
F-2-31
The leading edge sensor performs both this detection and paper feed detection. Therefore, the engine controller cannot make a judgment of ‘Toner cartridge absent’
or ‘jam occurrence’ when jam occurs.
The engine controller judges this case as ‘Toner cartridge absent’ and notices it to the main controller.
If jam occurs when ‘Toner cartridge absent’ is detected, check if there is a fault in the leading edge sensor and the detection flag.
Engine controller
PS801="H"
Toner cartridge
detection flag
Top of paper
sensor detection flag
PS801
PS801="L"
Toner cartridge = Yes
Toner cartridge = No