Product Info

–48 V DC P ower Supply Module (PSM) Shelf Chapter 10: PSM Shelf R eplacement Procedures
Prior to replacing the –48 V DC PSM shelf , the UBS Macro BTS site signaling is shutdown (i.e.,
disable the BTS site) then the UBS Macro BTS frame is powered down.
Table 10 -1 –48 V DC PSM Shelf R eplacement Conditions
FRU
Ref Designator What to Shutdown...
–48 V DC P ower
Supply Module
(PSM) shelf
–48 V DC PSM shelf Shutdown site signaling functions and then power
down the frame.
Required items
Documents
• 1X UBS Macro BTS Optimization/A TP manual.
Tools
• T orque driver
• T25 TORX driver
Torque requirements
• PSM shelf mounting screws; 4.77 N -m (42 in -lb)
• PSM captive M4 retaining thumbscrew , 2.37 N -m (21 in -lb)
Replacement unit
• –48 V DC PSM shelf assembly (Motorola model STHN4089)
Prerequisites
Coordinate this repair task with the OMCR operator .
10 -4 68P09283A64 -3
FOA SEP 2007