Replacing The (B1) Fan; Procedure - HP 8511A Operating And Service Manual

Replacing the (B1) Fan

WARNING

Procedure

Service and Replaceable Parts
Replacement Procedures
Turn the test set OFF and disconnect the power cord from the mains.
Electrocution can result if power is not removed from the test set prior to this
procedure.
To replace the fan (B1), you must remove the transformer (T1) so that the
ends of the fan wires can be unsoldered from the line module FL1. Refer to
the Table 6-1 on page 6-3 for the part numbers used.
1. Turn the test set on its right side.
2. Unplug the transformer connector at J2 on the A15 regulator board.
3. Using a large pozidriv screwdriver, remove the four screws and washers
that hold the transformer onto the rear panel.
4. Using a large pozidriv screwdriver, remove the screw that holds the
transformer angle bracket to the main deck. The transformer wires
soldered to the line module are short, so do not pull the transformer out
too far.
5. Carefully remove the transformer from the test set and put it on the
bench close to the test set.
6. Strip the heat shrink tubing off the two fan wires and unsolder the wires
for the line module. Cut any cable ties holding the fan wires to nearby
cables.
7. Using a small pozidriv screwdriver, remove the screw and lock washer
that secure the green/yellow fan ground wire to the top of the rear panel
frame.
8. Using a small pozidriv screwdriver, remove the four screws that hold the
fan to the rear panel and remove the fan.
6-8 HP 8511A Test Set Operating and Service Manual