The CPU (IC201) turns the pick-up solenoid OFF at the start of print operation. At the same time it puts the FAN MOTOR DRIVE signal (FANON) into "H" and

rotates the fan motor. Once the fan motor reaches at its prescribed rotational count, the FAN LOCK signal (FLOCK) is put into "L". When the FLOCK indicates

"L", the CPU determines the fan rotates normally. After the print operation is completed and the main motor stops, the CPU rotates the fan motor for approx. 30

sec. and puts the FANON into "L" to stop the fan motor.

The CPU determines the fan motor failure and notifies it to the video controller under the following condition.

1) The FAN LOCK signal (FLOCK) indicates "H" for more than approx. 10 sec. continuously during the fan motor is rotating.

2.6.2 Power Supply

2.6.2.1 Power Supply

2.6.2.1.1 Low-voltage Power Supply Circuit

LBP3370 / LBP3310

The low-voltage power supply circuit converts the AC power supply input from the inlet into the DC power supply and supplies to each load.

The AC power is supplied to the low-voltage power supply circuit in the engine controller when the printer switch is turned ON.

This supplied AC power is converted in this circuit into +24VDC, +5VDC, and +3.3VDC, which are required inside the printer. The +24VDC is supplied to drive

the load systems; such as the main motor, the scanner motor, and the solenoids etc, the high-voltage power supply circuit, and the options. The +5V is supplied to

the laser and the video controller. The +3.3V is supplied to the sensors and the ICs inside the engine controller PCB.

The +24VDC is divided into +24V and +24U. The +24V is supplied from the low-voltage power supply circuit at all time, and the +24U is interrupted when the

door switch (SW301) is turned OFF according to the cartridge cover open. The +24U is supplied to the high-voltage power supply circuit on the engine controller.

It also functions as the DOOR OPEN DETECTION signal and the CPU detects the door open using this signal.

Engine controller PCB

Fan motor drive circuit

+3.3V

+24V

J209-3

J209-1

J209-2

F-2-21

Fan motor

FM1

FANON