- HP Printer User Manual

90 MFP unit explanation ENWW
First paper feed control
The first paper feed from Tray 1 takes place
as the result of the transmission of the drive
force from M6 (loop roller) to the pick roller.
M6 is controlled by PRCB (printer control
board). The related signal is PS36 (loop).
1 Operation
a When printing of the first copy starts
M6 (loop) is turned on at the timing that
is determined by the P counter (that
starts when printing starts), thus starting
feed of paper.
M6 is stopped temporarily after lapse of
a specified time from turning on of PS44
(registration) by the leading edge of
paper, a loop is formed by registration
rollers, and the paper is fed to the
transfer unit.
b When printing of the second or
subsequent copy After lapse of the
specified time from turning off of PS44
(registration) by the trailing edge of the
preceding paper.
2 Signals
a PRCB input signals
1 LOOP_PS (PS36 to PRCB)
Paper passage detection signal
[L]: Paper does not exist.
[H]: Paper exist.
2 2ND_PS (PS44 to PRCB)
Second paper feed reference timing
detection signal
[L]: Paper exists.
[H]: Paper does not exist.
b PRCB output signals
1 A and /A (PRCB to M6)
A-phase drive control pulse signal for
M6
2 B and /B (PRCB to M6)
B-phase drive control pulse signal for
M6
Paper up/down control
Paper in Tray 1 is pushed up/down by M20
(up/down motor/BP). M20 is controlled by
PRCB (printer control board). Related
signals are PS34 (tray upper limit /BP) and
PS35 (tray lower limit /BP).
Paper size VR/BP (VR5)
Paper size PS/2-BP (PS32)
Paper size PS/1-BP (PS31)
By-pass tray
PRCB
PS36
PS44
24V
24V
A
/A
B
/B
24V2
P.GND
5V2
S.GND
M6
5V3
LOOP_PS
S.GND
5V2
2ND_PS
S.GND
Second paper
feed unit
PS34
PRCB
DCPS
5V2
S.GND
BPUDM_A
BPUDM_B
5V3
BPUP_PS
SGND
PS35
5V3
BPDN_PS
SGND
M20