Power Module And Transformer; Model 7475A; Power Module Removal - HP 7475A Service Manual

Section VI
i.
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.
j. Replace all parts in reverse order.
6-80. POWER MODULE AND TRANSFORMER
a. Remove the top case. Refer to Top Case Removal.
b. Remove the chassis assembly. Refer to Printed
Circuit Assembly Removal, steps b. through f.
NOTE
The transformer is held in place by
the power module molding.
c. Remove the safety earth (ground) wire screw at
the left end of the power module. See Figure 6-20.
d. Disconnect the three-wire secondary power cable
from the printed circuit assembly.
e. Disconnect the primary wires from the transformer.
f. Remove the screw in the power module. See Figure
6-20.
g. Lift the left end of the module. The right end is
held by a tab which fits into the base plate.
h. Replace in reverse order.
7475·A·28·1
When connecting the transformer
primary wires, refer to Section I, Line
Voltage and Fuse Selection, for correct
wiring.
POWER MODULE
MOUNTING SCREW
Model 7475A
WARNING'
To protect against possible electrical
shock, Be sure
to
replace the safety earth
(ground) wire and tighten the screw
securely. See Figure 6-20.
6-81.
POWER MODULE WIRING
6-82. The power module is available as a prewired unit
including the power input connector, switch, and fuse-
holder (less cap and fuse). The part number for this
assembly is 07470-60120. This does not include the power
transformer. It is recommended that if replacement of
any part of the unit is required, the entire unit be replaced.
However, if this it is not possible and any part must be
replaced separately, refer to Figure 6-21 for the correct
wiring information.
6-83. CLEANING
WARNING
I
Disconnect the plotter from the power
source prior to performing any mainte-
nance. DO NOT allow water to run
onto electrical components and circuits
or through openings in the enclosure as
this may create a shock hazard.
Do not attempt to clean the microgrip
drive wheels. Cleaning solutions may
dissolve the adhesive which secures the
grit particles to the wheels.
r'\
;~SAFETY
EARTH
(GROUND) WIRE
SCREW
Figure 6-20. Power Module Removal
6-16