Service Manual

GSM-204-523
Replacing a Tx block
31st Oct 01
Maint. 3–34
Maintenance Information: Horizon macro outdoor
CONTROLLED INTRODUCTION
68P02902W04-A
Replacing a Tx block
Preconditions
to Tx block
replacement
WARNING Ensure that RF power is OFF before disconnecting RF
cables. Severe burns may result if RF power is ON when
cables are disconnected.
CAUTION An earthing wrist strap must be worn when handling Tx
blocks. An ESP earthing connection point is provided
above the leftmost PSM.
There are three slots for Tx blocks in the top panel basket of a cabinet, above
the CTUs. There are four types of Tx block: DCF, TDF, DDF and HCU.
Replacing a Tx block requires the removal of RF transmitter power for the
CTU(s) that connect with the faulty Tx block. It is therefore advisable to perform
this procedure during periods of low traffic. The OMC-R should be notified of
imminent repair activity.
It is important to ensure that all Tx Block M6 screw locations have a screw in
place and tightened to the correct torque (see Overview of FRU replacement
procedures in this chapter). This is to ensure correct EMC shielding and
general containment.