Basic Sequense; Basic Operation Sequence; Power-On Sequence - Canon LBP2900 series Service Manual

Chapter 2

2.2 Basic Sequense

2.2.1 Basic Operation Sequence

The operation sequence of this printer is controller by the microprocessor (CPU) on the engine controller PCB. The following diagram shows the purposes
of each periods from power ON until the main motor stops after the completion of printing. See the timing chart.
WAIT
(Wait)
STBY
(Standby)
INTR
(Initial rotation)
PRINT
(Print)
LSTR
(Last rotation)

2.2.2 Power-on sequence

The following is the sequence from power ON until the engine controller enters STBY mode.
1) Power ON
2) CPU initialization
3) Video interface communication start
4) Residual paper check
Checks the sensors for any residual paper.
5) Main motor initial drive
6) Fixing heater initial drive
Drive the fixing heater so that the fixing unit reaches its targeted temperature of 100 deg C.
7) Scanner motor initial drive
8) High-voltage control
Clean the transfer sharging roller.
9) Failure/ abnormality check
Detects scanner failure, fixing unit failure and door open during the periods mentioned
above.
2-2
Period
From power-ON until the end To clean the drum surface
of the main motor initial of potential and to clean
rotation. the transfer charging
roller.
From the end of the WAIT To keep the printer ready
period or the LSTR period to print.
until the input of the pick-up
command from the video
controller. Or, from the end of
the LSTR period until power-
OFF.
From the input of the print To stabilize the
command from the video photosensiteive drum
controller until the pick up sensitivity in preparation
solenoid is turned ON for printing,Also to clean
the transfer charging
roller.
From the end of the initial To form image on the
rotation until the primary high- photosensitive drum
voltage is turned OFF. according to the video
signals input from the
interface controller, and
transfers the image to
paper.
From the primary high-voltage Delivers the final page and
is turned OFF until the main cleans the transfer
motor stops rotating. charging roller.
T-2-1
Purpose
Toner cartridge in/out detection is
executed.
As soon as the print command is
input from the video controller, the
printer enters the INITIAL
ROTATION period.
Remarks
0007-9885
0007-9887