Service Manual

GSM-205-523
Replacing a CTU
31st Oct 01
Maintenance Information: Horizon macro indoor
68P02902W09-B
CONTROLLED INTRODUCTION
Maint. 2–19
Replacing a CTU
Preconditions
for CTU
replacement
There are up to six CTUs in a cabinet. Replacing a CTU requires removal of RF
transmitter power for that CTU; it is therefore advisable to perform this
procedure during periods of low traffic. The OMC-R should be notified of
imminent repair activity.
NOTE
The CTU replacement procedure is the same for all CTUs,
regardless of frequency rating.
View of CTU
Figure 2-9 shows a view of a CTU with key features identified.
Tx OUT
CONNECTOR
Tx STATUS LED
HANDLE
M4 MODULE ATTACHMENT
SCREW
M4 MODULE ATTACHMENT
SCREW
TTY INTERFACE
CONTROL
PROCESSOR
TEST INTERFACE
RADIO STATUS LED
RECESSED MANUAL
RESET BUTTON (if fitted)
Rx A
Rx B
LOOPBACK
TEST PORT (L)
BACKPLANE POWER AND
SIGNAL CONNECTOR
Figure 2-9 CTU view with key features