Handbook

PBL UHF1/1A 1 & 2 Air Interface
Maintenance Handbook
H/book Number:-60-055900HBKM
Issue No:-2
Date:-20/10/2003
Page:-
83 of 85
7.3 Care of Modules
7.3.1 General Comments
Many of the active modules contain semiconductor devices utilising MOS technology, which
can be damaged by electrostatic discharge. Correct handling of such modules is mandatory to
ensure their long-term reliability.
To prevent damage to a module, it must be withdrawn/inserted with care. The module may
have connectors on its underside, which might not be visible to the service operative.
7.3.2 Module Removal (LNA’s, general procedure):
The following general rules should be followed to remove a module:
1 Remove power to the unit
2 Remove all visible connectors (RF, DC & alarm)
3 Release module retaining screws.
4 Slowly but firmly, pull the module straight out of its position. Take care not to twist/turn
the module during withdrawal. (When the module is loose, care may be needed, as there
may be concealed connections underneath).
7.3.3 Module Replacement (general):
1 Carefully align the module into its location then slowly push the module directly straight
into its position, taking care not to twist/turn it during insertion.
2 Reconnect all connectors, RF, alarm, power etc.,(concealed connectors may have to be
connected first).
3 Replace retaining screws (if any).
4 Double-check all connections before applying power.
7.3.4 Power Amplifiers
1) Remove power to the unit. (Switch off @ mains/battery, or remove DC in connector)
2) Remove alarm wires from alarm screw terminal block or disconnect multi-way alarm
connector.
3) Carefully disconnect the RF input and output coaxial connectors (usually SMA)
If alarm board removal is not required, go to step 5.
4) There is (usually) a plate attached to the alarm board which fixes it to the amplifier,
remove its retaining screws and the alarm board can be withdrawn from the amplifier in
its entirety. On certain types of amplifier the alarm board is not mounted on a dedicated
mounting plate; in this case it will have to firstly be removed by unscrewing it from the
mounting pillars, in most cases, the pillars will not have not have to be removed before
lifting the amplifier.