Nokia NPM-2NX Troubleshooting Manual page 38

NPM-2NX
Troubleshooting
Check signal level
at RX band filter
Z802 input
OK
Check signal level
at mix1_B input, L810
OK
Check signal level
at IF filter Z804
input (133.2 MHz, R803)
OK
Check signal level
at IF filter Z804
output (133.2
MHz), R804
OK
Check signal level
at RX I/Q J808,
J809, J818, J819
OK
Check UEM and
start baseband
troubleshooting
Step 1. General checking
The fastest way to get overview of RX status is to measure RSSI (Received Signal
Strength Indicator) level. This can be done by using signal generator and Phoenix. Note
that this is useful only if the phone has been calibrated when it was OK and the mal-
function have occured after tunings.
1) Set signal generator frequency to 1960.06771 MHz and level to -80 dBm.
2) Select RSSI measurement UI in Phoenix (maintenance => GSM RSSI Meas).
3) Set Band to GSM1900 and Rx/Tx channel to 661
Page 38
Not OK
Not OK
Not OK
Measure VR4 from L815
and L814 pads
Not OK
Check components
L815,
L814 etc.
Not OK
Replace IF filter
Z804
Not OK
Start synthesizer
troubleshooting
ãNokia Corporation
CCS Technical Documentation
Check components
around lna and
measure supply
voltages
Replace RX band
filter Z802
OK
Replace Safari N801
OK
Start synthesizer
troubleshooting
OK
Replace Safari
N801
Issue 1 07/02