
NPM-10
Troubleshooting Instructions RF
CCS Technical Documentation
Page 18
Nokia Corporation Confidential
Issue 1 03/2003
Troubleshooting Chart for PCS Receiver
Figure 10: GSM1900 receiver troubleshooting chart
By measuring with an oscilloscope at RXIP or RXQP on a working GSM1900 receiver, the
following picture should be seen.
Signal amplitude peak-peak 416 mV
DC offset 1.35 V
Apply -55 dBm
1960 MHz,
offset 67.71 kHz
from generator to
antenna connector
Oscilloscope at
RX I/Q signal
416 mVpp
DC offset 1.35 V
freq. 67.68 kHz
PCS chain
functional
Check
Antenna switch
at RX 1900 Z700
-58 dBm
Oscilloscope
check VANT1 and
VANT2 at Z700
signal 0V
Spectrum analyzer
PCS SAW filter
Z601
output -66 dBm
Spectrum analyzer
Check signal after
inductors L611 and
L601
-66 dBm
Check SAW filter
Z601
Oscilloscope
VRX 2.7 V
check Mjoelner
serial interface
Check inductors
L611, L601
Check Base band
Check
Antenna switch
Check Mjoelner
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
YES
YES
YES
1
2
3
4
1
2
3
4
5
6