Nokia 7600 - GSM Rx Troubleshooting

NMM-3 Company Confidential
6-Troubleshooting CCS Technical Documentation
Page 6-20 Copyright  2003 Nokia Corporation Issue 1 (11/2003)
Company Confidential
GSM900 RX Troubleshooting
Y
es
No
No
No
No
Y
es
Apply a –85dBm
942.46771MHz signal
from generator to RF
connector
Scope at
GRXI/GRXQ
Signal 1.3Vpp
DC Offset=1.2V
Freq=67.7KHz
900MHz chain
functional
Change
generator
level to
–50dBm
Is spectrum analyser
Ant Switch output
-53dBm?
Spectrum analyser
ant switch Input
-51dBm
Spectrum
analyser
V
CO output
3769.6MHz
-20dBm
Scope
V
ant_1 =0
V
In Rx mode
Check
ant switch
Check
Helgo
Y
es
Y
es
Y
es
Y
es
Y
es
Spectrum analyser
Helgo Inputs
-54dBm
Check
V
R2,VR3,VR4,VR5=2.8
V
Helgo serial interface
Baseband
Troubleshooting
Synthesizer
troubleshooting
No
No
Y
es
Y
es
Check
L633,L634
No
Phoenix Settings:
Band:GSM900
Active unit:RX
Op Mode:Continuous
Rx/Tx Chan:37
AGC:maximum (default)
Check C575 &
RF connector
HELGO
Troubleshooting