Gsm1800 Rx Troubleshooting - Nokia 7600 Troubleshooting Manual

CCS Technical Documentation

GSM1800 RX Troubleshooting

Phoenix Settings:
Band:GSM1800
Active unit:RX
Op Mode:Continuous
Rx/Tx Chan:700
AGC:maximum (default)
Yes
Apply a –85dBm
1842.86771MHz signal
from generator to RF
connector
Yes
Scope at Spectrum
No
GRXI/GRXQ analyser
Signal 1.3Vpp
VCO Output
DC Offset=1.2V
3685.6MHz
Freq=67.7KHz -20dBm
Yes
1800MHz Synthesizer
Chain
troubleshooting
Functional
Issue 1 (11/2003)
Company Confidential
Yes
Yes
Change
generator
level to
–50dBm
No
Copyright  2003 Nokia Corporation
Company Confidential
No
Is spectrum analyser
ant switch output
-54dBm?
Check
Helgo
Yes
No
Spectrum analyser
Helgo inputs
-55dBm
Yes
Check
VR2,VR3,VR4,VR5=2.8V
Helgo serial interface
Yes
HELGO
Troubleshooting
NMM-3
6-Troubleshooting
Check C575 &
RF connector
No
Spectrum analyser
ant switch input
-51dBm
Yes
No
Scope
Vant_1 =0V
In Rx mode
Yes
Check
Ant Switch
Check
L635,L636
No
Baseband
Troubleshooting
Page 6-21