PAMS
Technical Documentation
NSC/W–1/3
Disassembly & Troubleshooting Instructions
Page 23
Original 11/99
Receiver Fault TDMA800
Apply 879.00 MHz
–50dBm signal to
external RF–connector
X991.
Check 3 multiplier
output level TP2LU
V: >150 mVpp
N
N
N
Check input level
at duplex filter (Z910)
input
P: ~–52 dBm
Check input level at
frontend (N701) pin 7
P:~–50 dBm
Check output level at
LNA out, pin 10
Check RF level of
COBBA_D pin no 10
P: ~–13 dBm
Check UHF Vcnt TP31
V: 2.0...2.5 V
Start synthesizer
troubleshooting
TDMA800
RX–chain OK
Y
N
N
Y
N
Start synthesizer
troubleshooting
Change EXT RF
Connector
Note!
Check all soldering and components
in antenna circuit before changing
N
Y
Y
Change duplex filter or
L701
Note!
Check all soldering and discrete
components of frontend.
Change N701
Y
Note!
AG2 is on , TP11LU
Check MXR RF level
P:~0–2 dB less than in
Change RX band filter
Z701
Note!
Check all soldering
N
Y
Check all components around of N701
N
Y
N750, pin 42
pin 12
LNA output pin no. 10
P:~–50 dBm