HP 85020A Operating And Service Manual page 60

Service
Model 85020A/B
5. Unsolder the two white/black wires and the white/red wire from
the solder lag and connector pins on the Al bridqe housing.
6. Turn over the instrument. Remove the printed mylar serial
number label and the aluminum foil cover from the back of the
extruded frame. Four screws will be exposed.
7. Remove the four screws from the back of the instrument.
8. Remove the bridqe microcircuit from the extruded frame by
tilting it up to clear the preamplifier assembly. Take care
not to lose the stainless steel spacer under the microcircuit
assembly.
Figure 8-6. Al Bridge Microcircuit Assembly
To install the replacement bridqe assembly, proceed as follows:
1. Install the spacer over the screw holes and the bridqe
assembly in the instrument frame over the spacer.
2. Replace the four screws.
3. Remove the protective backing from the aluminum foil and anplv
it to the back of the frame.
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