Ricoh IS2022, Service Manual, Page: 29 / 313

ELECTRICAL COMPONENT DESCRIPTIONS 10 August, 2001
1-12
Symbol Name Function
S5 Original Length 2
Detects original length. This is one of the APS (Auto
Paper Select) sensors.
S6 Toner Density (TD)
Detects the amount of toner inside the development
unit.
S7 1st Paper End
Informs the CPU when the 1st paper tray runs out of
paper.
S8 2nd Paper End
Informs the CPU when the 2nd paper tray runs out of
paper.
S9 Image Density (ID)
Detects the density of various patterns and the
reflectivity of the drum for process control.
S10 Paper Overflow Detects paper overflow in the built-in copy tray.
S11 Paper Exit Detects misfeeds.
S12 Upper Relay Detects misfeeds.
S13 Lower Relay Detects misfeeds.
S14 Registration
Detects misfeeds and controls registration clutch off-
on timing.
S15 1st Paper Lift
Detects when the paper in the 1st paper tray is at the
feed height.
S16 2nd Paper Lift
Detects when the paper in the 2nd paper tray is at
the feed height.
S17 1st Paper Height – 1 Detects the amount of paper in the 1st paper tray.
S18 1st Paper Height – 2 Detects the amount of paper in the 1st paper tray.
S19 2nd Paper Height – 1 Detects the amount of paper in the 2nd paper tray.
S20 2nd Paper Height – 2 Detects the amount of paper in the 2nd paper tray.
PCBs
PCB1 Controller
Controls all applications both directly and through
other control boards.
PCB2 PSU (Power Supply Unit)
Provides dc power to the system and ac power to
the fusing lamp and heaters.
PCB3
SBCU (Scanner & Base
Engine Control Unit) Controls the fusing lamp and the mechanical parts of
the machine.
PCB4 SBU (Sensor Board Unit)
Contains the CCD, and outputs a video signal to the
BICU board.
PCB5 Lamp Stabilizer Stabilizes the power to the exposure lamp.
PCB6 LDD (Laser Diode Driver) Controls the laser diode.
PCB7 Operation Panel Controls the operation panel.
PCB8 High Voltage Supply
Supplies high voltage to the drum charge roller,
development roller, and transfer roller.
PCB9 Memory (Option)
Expands the memory capacity for the copier, printer,
and scanner features.
PCB10
IPU (Image Processing
Unit)
Performs the image processing functions.
Solenoids
SOL1 Fusing Drive Release Releases the drive for the fusing unit.
Lamps
L1 Exposure Lamp
Applies high intensity light to the original for
exposure.