HP 7942 Service Manual page 149

Service Notes
7942 and 7946
8-8
Fit the plastic insulator, part no 07942-40004, and metal spacer, part no. 07942-20001, as
follows:
1. Set the drive LINE- switch to the 0 (out) position and dis-
connect the power cord from the -AC LINE connector on
the rear panel.
2. Remove the power supply from the mainframe assembly.
(Refer to the HP 7942/7946 Service Manual, paragraph 5-11,
for removal instructions.)
3. At the rear left of the the power supply, detach the the plas-
tic spacer which secures the power supply shield, part no.
07942-20004, to the power supply. See figure 1.
4. Remove the paper backing from the adhesive surface of the
plastic insulator.
5. With the power supply in a vertical position, hold the plastic
insulator on the edge of the power supply at the location
shown in figure
1.
6. Press the power supply shield onto the adhesive surface of
the insulator.
7. Reattach the power supply shield to the power supply with
the plastic spacer.
I
CAUTION
I
Metal spacer. part no. 07942-20001, must be used in place of the spacer removed in
step 2. Failure to observe this precaution could result in a power supply output
being shorted to ground.
All the power supply attaching parts (two TIS screws, one TIO screw and spacer,
part no. 07942-20001) must be reinstalled. These parts are needed to properly
ground the power supply to the mainframe assembly.