Ricoh B234 Service Manual page 772

ELECTRICAL COMPONENT DESCRIPTIONS
Number Name
PCBs
PCB6 IPU
PCB7 Interlock Relay Board
PCB8 LDB
PCB9 Lamp Regulator (Left)
PCB10 Lamp Regulator (Right)
PCB11 Laser Synchronization Detector
Board
PCB12 MCU
PCB13 Mother Board
PCB14 PSU-Ea
PCB15 PSU-Eb
PCB16 PSU-c
PCB17 Polygon Mirror Motor Control Board
PCB18 SBU
PCB19 SIB
PCB20 OPU
PCB21 Image Position Sensor Board
(Tray)
PCB22 Image Position Sensor Board
(Duplex)
PCB23 SD Slot Board (Service)
PCB24 Operation Panel
B234/B235/B236/D101/D102/D103
Description
IPU (Image Processing Unit): Contains
large-scale integrated circuits that process
the digital data sent from the SBU. Some
processes may require enough working
memory to store a page of image data.
The microswitches that toggle the power to
the laser unit off/on when the doors are
open/closed are mounted on this small
board.
LDB (Laser Diode Board): The LDB contains
and controls the laser diodes..
Controls the Xenon exposure lamp in the flat
bed scanner
Controls the Xenon exposure lamp in the flat
bed scanner
Detects when the laser is about to start
another main scan line across the OPC
MCU (Motor Control Unit). Controls the
scanner motor.
Controls the memory and all peripheral
devices. The GW architecture allows the
board to control all applications, i.e. copying,
printing, and scanning. In order to add an
option (printer, scanner), the appropriate
ROM DIMM must be installed on the
controller.
PSU-E (Power Supply Unit-Engine A):
Supplies DC power for the IOB, LCT, OPU,
IPU.
PSU-E (Power Supply Unit-Engine B):
Supplies DC power for the two PSU fans, the
MCU and the Relay Interlock Switch.
PSU-C (Power Supply Unit-Controller):
Supplies DC power for the controller.
Controls the polygon motor.
SBU (Sensor Board Unit): Contains the CCD.
Converts the CCD output to digital before
sensing it to the IPU (Image Processing
Unit).
The SIB (Scanner Interface Board) controls
the scanner, and serves as the signal I/F
board for the IPU and MCU.
The operation panel unit interfaces with the
CPU and runs the copier user interface.
The image position sensor in the paper bank
that detects the edges of paper fed from the
copier paper bank (trays 1, 2, 3) for image
position correction during simplex printing.
The image position sensor in the paper bank
that detects the edges of paper fed from the
copier paper bank (trays 1, 2, 3) for image
position correction of during duplex printing..
The board for the service slot (C3).
The board that controls the operation of the
6-10 SM