Service manual

BY-PASS TRAY
2-L-3
2 UNIT EXPLANATION
[4] Paper Up/down Control
By-pass tray paper is moved up and down by transmit-
ting the drive force of M22 (up/down (by-pass)). M22 is
controlled directly by PRCB (printer control board).
Related signals are PS23 (tray upper limit (by-pass
tray)) and PS43 (tray lower limit (by-pass tray)).
1. Operation
a. Paper up/down control
M22 is turned ON a fixed time to push up paper.
When PS23 detects the upper limit of paper and
is turned ON, M22 is turned OFF to stop pushing
up paper. When paper is fed and PS23 is turned
OFF, M22 turns ON once more to maintain the
upper limit position of the paper.
b. Paper up timing
(1) ON timing
At start of copying
(2) OFF timing
M22 is turned OFF when PS23 is turned ON.
c. Paper down timing
(1) ON timing
Turns ON when there is no paper or when paper
jaming takes place.
(2) OFF timing
M22 is turned OFF when PS43 is turned ON.
2. Signals
a. Input signals
(1) PS23 (PS23 to PRCB)
Paper upper limit position detection signal (by-
pass tray).
[L]: Detected
[H]:Not detected
(2) PS43 (PS43 to PRCB)
Paper lower limit position detection signal (by-
pass tray).
[L]: Detected
[H]:Not detected
b. Output signal
(1) M22 DRIVE 1, 2 (PRCB to M22)
M22 drive control signal.
PRCB
DCPS1
DCPS2
PS23
5VDC
PS23
SGND
5VDC
SGND
PS43
24VDC
PGND
PS43
M22 DRIVE 1
M22 DRIVE 2
M22
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