Service manual

Chapter 3
3-5
The keys are monitored, and the LCD and LEDs are driven.
LCD Function
The LCD consisting of 2 lines of 20 characters is controlled according to the display signals from the image processor
PCB.
Serial Communication Control
The state of the control keys is monitored based on serial communications with the image processor PCB. LCD and
LED drive data are received.
3.1.6 Power Supply PCB
0006-3962
Switching Regulator
The following is generated using power from the power outlet for loads: +24 DC, +12 VDC, +5 VSDC, +5 VDC,
+3.3 VSDC, +3.3 VDC.
3.1.7 Analog Processor PCB
0006-3966
The analog image data read by the contact sensor is converted into digital image data and sent to the ASIC of the
image processor PCB.
3.1.8 Sensor PCB
0006-3987
The signals from the ADF (copyboard cover) open/close sensor and the contact sensor home position sensor are sent
out to the image processor PCB via the analog processor PCB.
3.1.9 Laser Driver/BD PCB
0006-3989
The image signals (VD0, VD0*) from the image processor PCB is converted into data used for laser adjustment (to
cause the laser diode to emit a laser beam). Also, the generated laser beam is detected, and the laser beam detection
signal (BDI*) is sent to the DC controller PCB.
3.1.10 Main Motor/Scanner Motor Driver
0006-3991
The main motor/scanner motor is driven according to the drive signals from the DC controller PCB.
3.1.11 Printer Controller PCB (if equipped with printer functions)
0006-3996
The communications with the PC are controlled. The image data from the PC is converted into print data for the
machine, and is sent to the image processor PCB.
Communication Control
Communications with the PC are controlled using a bi-directional parallel interface (IEEE std 1284-1994) or USB