Paper Drive Motor Assembly Removal; Pen Carousel Housing; Paper Drive Motor And Solenoid Cables; Paper Drive Motor Clamp And Pen Drop Shield - HP 7475A Service Manual

Section VI
c. Remove the screw that secures the pen carousel
housing to the chassis assembly. See Figure 6-9.
PEN CAROUSEL
HOUSING
PEN
CAROUSEL
PEN CAROUSEL
HOUSING SCREW
7475-A-18-1
Figure 6-9. Pen Carousel Housing
d. Tip the pen carousel housing forward and lift
straight up being careful not to catch the cable
connector on the chassis assembly.
e. To reassemble, reverse steps a. through d.
6-67. PAPER DRIVE MOTOR ASSEMBLY
REMOVAL
a. Remove the top case. Refer to Top Case Removal.
Do not remove the encoder printed
circuit assembly or the drive coupler
from the motor. The entire unit must
be assembled and calibrated at the
factory.
b. Disconnect the paper drive motor cable (twisted
pair) from
J3
and the flat encoder cable from
Jl
on the main printed circuit assembly. See Figure
6-10.
c. Remove the pen drop shield. See Figure 6-11.
d. Loosen the motor clamp and remove the motor
from its mounting. See Figure 6-11.
e. When replacing the motor, make sure that the
rubber 0-rings on the drive shaft coupler and the
motor shaft coupler fit inside the grooves of the
coupler ring, and the boss (key) on the underside
of the motor casting fits into the corresponding
hole in the chassis. See Figure 6-12.
f. Make sure the pen carriage slider rod is all the
way to the left, then replace the motor clamp. The
arm on the clamp should hold the slider rod to
the left. Tighten the clamp screw securely.
g. Loosen the clamping screw in the paper drive
shaft coupler just enough to allow the coupler to
6-10
PAPER DRIVE
MOTOR
ASSEMBLY
ENCODER
CABLE (IN J1)
PEN SOLENOID
CABLE (IN J2)
PAPER DRIVE
MOTOR CABLE
(IN J3)
7475-A-19-1
Model 7475A
Figure 6-10. Paper Drive Motor and Solenoid Cables
PAPER DRIVE
PEN DROP MOTOR CLAMP PAPER DRIVE
SHIELD SCREW SCREW MOTOR CLAMP
PEN DROP
SHIELD
B/A~l AIA4
••
PEN s1zr
PAPER DRIVE
MOTOR ASSEMBLY
Figure 6-11. Paper Drive Motor Clamp and Pen Drop
Shield
slide on the shaft. Make sure the nut remains in
the coupler.
h. Hold the drive shaft to the left by pushing (with a
finger) on the left gritwheel, and push the drive
shaft coupler to the right (with another finger) so
that the coupler parts fit together snugly. Tighten
the shaft coupler clamping screw securely.