Ricoh B079, Service Manual

Page: 338 / 948

BOARD STRUCTURE
B079/B082 6-6 SM
IOB
The IOB (Input/Output Board) handles the following functions:
•
Drive control for the sensors, motors, and solenoids of the main unit
•
PWM control for the high voltage supply board
• Serial interface with peripherals
•
Fusing control
NOTE: The IOB is now located directly behind the rear covers for easier
access. The machine no longer contains the PFB (Paper Function
Board). The functions of the PFB (paper feed control) have been taken
over by the IOB. The same IOB is used for both the B079 and B082 but
the DIP switches must be set correctly for each. See Section “3
Replacement and Adjustment” for details.
SIB (Scanner Interface Board): Controls the scanner, and serves as the signal I/F
board for the SBU and the OPU. The SIB passes signals between the BICU and
the scanner unit components, and transmits video signals from the SBU to the
BICU.
OPU (Operation Panel Unit): Controls operation panel and display.
SBU (Sensor Board Unit): Receives analog signals from the CCD and converts
them into digital signals.
LDDR (Laser Diode Driver): The LD driver circuit board.
MDB (Motor Drive Board): Controls the scanner motor.
Mother Board: This board interfaces the controller and the BICU and FCU.
FCU (Facsimile Control Unit): Controls fax communications and fax features.