Service manual
TRAY 3 PAPER FEED UNIT
2-K-3
2 UNIT EXPLANATION
[3] First Paper Feed Control
The 1st paper feed from tray 3 takes place as the result
of the transmission of the drive force from M4 (paper
feed) to each paper feed roller, via MC7 (feed MC3)
and MC8 (pre-registration MC3). SD10 (pick up SD3)
causes the roller to pick up paper. The above opera-
tions are controlled by the PRCB (printer control
board). Related signals are PS51 (paper feed 3), and
PS52 (paper pre-registration 3).
1. Operation
a. First paper feed timing (feed MC drive)
(1) When printing of the first copy starts
Timing that is determined by the P counter from
when copying starts.
(2) When printing of the second copy starts
When PS51 turns OFF after the first paper feed
detection.
(3) OFF timing
After a specified count from turning ON of PS50.
*Changeable in 36 mode.
b. Feed timing (pre-registration clutch drive)
(1) ON timing
First sheet: When a preset time interval has
passed after turning ON of MC7.
Second sheet:When a preset time interval has
passed after turning ON of MC1
(registration).
(2) OFF timing
When PS19 is turned OFF.
2. Signals
a. PRCB input signals
(1) PS51 (PS51 to PRCB)
Paper passage detection signal.
[L]: Paper passed
[H]:Paper not passed
(2) PS52 (PS52 to PRCB)
First paper feed paper detection signal.
[L]: Paper exists
[H]:Paper does not exist
b. PRCB output signals
(1) MC7 CONT (PRCB to MC7)
MC7 drive control signal.
[L]: MC7 ON
[H]:MC7 OFF
(2) MC8 CONT (PRCB to MC8)
MC8 drive control signal.
[L]: MC8 ON
[H]:MC8 OFF
(3) SD10 CONT (PRCB to SD10)
SD10 drive control signal.
[L]: SD10 ON
[H]:SD10 OFF
PRCB
DCPS1
DCPS2
PS51
PS52
M4 CLK
M4 F/R
M4 CONT
M4 EM
5VDC
SGND
5VDC
PS51
SGND
PS52
24VDC
PGND
24VDC
PGND
M4
MC7
MC8
MC10
24VDC
MC7 CONT
MC8 CONT
MC10 CONT
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