Tdma 1900Rx - Nokia NSW-6 Series Disassembly & Troubleshooting Instructions

NSW-6
Disassembly & Troubleshooting

TDMA 1900RX

Apply 1960.02 MHz
–50dBm signal to
Antenna interface
Check RF level of
COBBA_D pin no 10
Check UHF Vcnt
V: 2.0...3.5V
N870, pin3
Check 3 multiplier
output level at C745
V: >80 mVpp
Check input level
of duplex filter (Z960)
P: ≅ –50dBm
Check input level of
frontend N721, pin7
P: ≅ –55dBm
Check output level at
LNA out, pin10
P: ≅ –50dBm
Check MXR RF level
pin12
P: ≅ –55dBm
Check MXR IF level,
F= 116.19 MHz,
pin14
Page 30
NOTE! If RX800 is OK, then RX1900
troubleshooting should be concentrated only on
Z960 and N721 area and surrounding components.
Y
TDMA1900
RX–chain is OK
N
N
N
Start synthesizer
troubleshooting
Y
N
Start synthesizer
troubleshooting
Y
N
Change diplexer Z970
Y
N
Change duplex filter or
L721
Y
N
Change N721
Y
N
Change RX band filter
Z726
Y
N
Check input level of
frontend N721, pin1
F=2076.21 MHz
Y
Change N721
E Nokia Mobile Phones Ltd.
PAMS Technical Documentation
Note!
Check all soldering and components
in antenna circuit before changing
Note!
Check all soldering and discrete
components of frontend.
Note!
AG2 is on =low gain state
N
Note!
Check all soldering
N
Start synthesizer
troubleshooting
Y
Note!
Check all components around of N721
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