Service manual
DEVELOPING UNIT
2-G-8
2 UNIT EXPLANATION
[9] FM2 (Developing Suction) Control
FM2 (Developing suction) is controlled by the PRCB
(printer control board) via the ACDB (AC drive board).
When the front right or left door of this machine opens
or closes, MS1 (interlock 1) or MS2 (interlock 2) oper-
ates to interrupt the DC power supply, stopping FM2.
1. Operation
a. ON timing
During idling: FM2 turns ON when M2 (drum)
turns ON.
During copying: FM2 turns ON when M1 (main)
turns ON.
b. OFF timing
During idling: FM2 turns OFF when M2 turns
OFF or in the specified interval after completion
of copying.
During copying: Always ON.
2. Signals
a. PRCB input signals
(1) FM2 EM (FM2 to PRCB)
FM2 fault detection signal.
[L]: FM2 is normal.
[H]:FM2 is abnormal.
(2) FM2 FEM (ACDB to PRCB)
Signal detecting whether the 24V fuse for FM2 is
blown.
[L]: Blown fuse is not detected.
[H]:Blown fuse is detected.
b. PRCB output signals
(1) FM2 CONT (PRCB to ACDB)
FM2 control signal.
[L]: FM2 ON
[H]: FM2 OFF
c. ACDB output signal
(1) FM2 DRIVE (ACDB to FM2)
FM2 drive signal.
[L]: FM2 OFF
[H]: FM2 ON
PRCB
DCPS2 ACDB
FM2 CONT
FM2 EM
FM2 FEM
FM2 DRIVE
PGND
24VDC
PGND
MS2 MS1
FM2
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