Toner Cartridge Absence/Presence Detection; Service Works; At Parts Replacement; Maintenance - Canon imageCLASS MF4890dw Service Manual

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Technical Overview > Image Formation System > Service Works > Notes on service works

■ Toner Cartridge Absence/Presence Detection

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
(PS751).
When the output result of the leading edge sensor (PS751) is L, it is judged that the Toner
cartridge is absent; If being H, it is judged that the Toner cartridge is present.
PS751
Leading edge
sensor detection flag
Toner
cartridge=No
PS751="L"
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 notifies it to the main
controller.
2 Technical Overview > Image Formation System > Service Works > Notes on service works
Engine controller
Toner cartridge
detection flag
Toner
cartridge=Yes
PS751="H"
F-2-27
If jam occurs when 'Toner cartridge absent' is detected, check if there is a fault in the leading
edge sensor and the detection flag.

Service Works

■ At parts replacement

No work is required for this product at parts replacement.

■ Maintenance

No periodically replaced parts, durable parts or periodical service is set for this product.

■ Notes on service works

None.
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