Brother 1660e - B/W Laser Printer, Service Manual

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4.4 Paper Jam Detection
The printer has a registration sensor and a paper eject sensor at the paper outlet to detect
whether the printed paper has been fed correctly. A paper jam is detected by whether the paper
is present at the sensor at the check periods programmed in the engine CPU memory. If the
engine CPU detects a paper jam, the main motor, paper feed motor and scanner motor is turned
off immediately and the jam status is transmitted to the video controller circuit.
A paper jam is detected in any of following conditions:
1) Paper exists at the paper ejection sensor or the registration sensor when power is
switched on. (JAM REAR or JAM INSIDE)
2) Paper has not reached the registration sensor within a specified time (JAM TRAYS).
3) Printed paper has not passed through the registration sensor within a specified time (JAM
INSIDE (1) ).
4) Printed paper has not reached the paper ejection sensor within a specified time (JAM
INSIDE (2) ).
5) Printed paper has not passed through the paper ejection sensor within a specified time
(JAM REAR).
Figure 2.22
Figure 2.21
Main motor
Registration
sensor
Pick-up
solenoid
STBY PRINT
Jam check
Jam Normal
3.75 sec 3.75 sec
Jam
3.67 sec 3.67 sec
Normal
Main motor
Registration
sensor
Paper feed
motor
Jam check
STBY PRINT
Jam inside (1)
Jam tray