Canon LBP-2000, Service Manual

Page: 109 / 222

CHAPTER 2
2 - 70
D . Detecting Jams
The feed paper sensor (PI201) is used to check the presence/absence of paper and to find out if
paper is moving correctly. It checks for a jam in terms of the presence/absence of paper over it at
such times as programmed in advance. When the CPU detects a jam, it will stop printing operation
and indicate the fact to the DC controller.
1 . Pickup delay jam
The video controller will identify a feed sensor pickup delay jam or a registration sensor pickup
delay jam as a pickup delay jam.
• Feed Paper Sensor Pickup Delay Jam
The feed paper sensor (PI201) does not detect the leading edge of paper within a specific period of
time after the feeding roller starts to rotate to move paper.
• Registration Paper Sensor Pickup Delay Jam
The registration paper sensor (PI101) does not detect the leading edge of paper within a specific
period of time after the feed sensor detects the leading edge of paper.
• Feed Sensor Pickup Delay Jam
PF pickup motor
Feed paper
sensor jam check
PF pickup clutch
PF feed paper
sensor
STBY
Pickup control
/PRNT signal IN
Jam message ON
Normal Error
2nd sheet picked up
Figure 2-7-6
• Registration Sensor Pickup Delay Jam
STBY
Pickup control
/PRNT signal IN Jam message ON
2nd sheet picked
Registration paper
sensor (PI101)
Registration paper
sensor jam check
PF1 feed
paper sensor
Normal
Error
Figure 2-7-7