HP 54520 Series Service Manual page 108

CAUTION
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To remove and replace an attenuator
To remove and replace an attenuator
Use the following procedure to remove and replace an attenuator assembly. When necessary,
refer to other removal procedures.
ELECTROSTATIC DISCHARGE!
Use grounded wrist straps and mats when servicing the main assembly. Electrostatic
discharge can damage electronic components.
Attenuators are not part of the main assembly. If the Main assembly is replaced, the
attenuators will have to be moved to the replacement assembly.
Remove the main assembly.
From the bottom of the main assembly, remove two screws that secure the
attenuator.
A 24pin connector, located at the rear of and inside the attenuator, connects it to
the PC board. With a gentle rocking or prying motion, lift the attenuator from the
PC board.
Use a small flat-blade screwdriver, prying at the rear between the attenuator and PC board, to
help control attenuator removal.
Reassemble the instrument by following the appropriate steps of all procedures.
If you permanently replace parts
If you have permanently changed any combination of main assembly, attenuator, or acquisition
hybrid, you will need to adjust the high-frequency pulse response on the affected channels. For
example:
If you permanently swap two attenuators or acquisition hybrids during troubleshooting, you
must adjust the channels affected.
If you replace one attenuator or hybrid, you must adjust that channel
If you replace the main assembly, you must adjust all channels.
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