Troubleshooting Diagram For Gsm850 Receiver - Nokia RH-18 Troubleshooting Instructions

RH-36

Troubleshooting diagram for GSM850 Receiver

Apply -55dBm
942.4 MHz
offset 67.71kHz
from generator
to
antenna conn
YES
Oscilloscope
at RX i/Q
signal 588mVpp
DC offset 1.35V
Freq.67.71kHz
YES
EGSM
chain
OK
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Figure 17: GSM850 Receiver troubleshootingt
Check RX/TX
NO
switch at
RX900
Z700
-56dBm
YES
Spectrum analyzer
EGSM SAW filter
Z602
output
-65dBm
YES
Spectrum analyzer
NO
check signal after
inductors
L602 and L603
-65DbM
YES
Oscilloscope
VRX 2.7V
NO
Check Mjoelner
serial
interface
Nokia Corporation.
CCS Technical Documentation
Oscilloscope
check
VC1 and VC2
at Z700
Signal = 0V
YES
Check
RX/TX
switch
NO
Check
SAW filter
Z602
Check
Inductor
L603, L602
Check
Baseband
NO
Check Mjoelner
YES
Issue 1 10/03