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3: Operation
3-68
Colorwriter LSR 2000 Printer
Service Guide
•
PS4 detects a flag width differing from that of the specified
rotational position flag.
•
PS4 does not detect the rotational position flag when the press
operation starts.
Toner cartridge pressure/separation failure
When the following phenomena are detected by the toner cartridge
position sensor (PS3), the DC controller is notified by the
mechanical controller which assesses them as toner cartridge
pressure/separation failures. The DC controller notifies the video
controller of the faults.
•
PS3 stays on for a certain period of time after the press
operation starts.
•
PS3 stays OFF for a certain period of time after the separation
operation starts.
Developing unit motor drive circuit
The developing unit motor (M3) uses a four-phase stepping motor.
The developing unit motor is controlled by the developing unit
motor driver (Q2003) on the mechanical controller.
The developing unit motor transmits the driving force to the
developing rotary and the toner cartridge press cam.
When the print sequence command is received, the CPU (Q2001)
in the mechanical controller sends the developing unit motor
control signals (DEVPHA, /DEVPHA, DEVPHB, /DEVPHB) and
the developing unit motor rotation rate select signal (DEVICH) to
the drum motor driver (Q2003) 0.2 second after the fixing unit
motor starts. Based on those signals, Q2003 supplies the drive signal
to the developing unit motor. 24VC is supplied for the drive power
supply.
When none of the toner cartridges have been installed, more
rotational force than usual is required because the rotary’s center of
gravity has moved away from the middle. As the mechanical
controller cannot recognize whether or not all cartridges are present
during operation of the toner cartridge detection function, the CPU
reduces the developing rotary rotation rate by setting the DEVICH
signal to “H” to drive the developing unit motor at half-speed.