Nokia 7600 - WCDMA Rx Troubleshooting

CCS Technical Documentation 6-Troubleshooting
Company Confidential NMM-3
Issue 1 (11/2003) Copyright  2003 Nokia Corporation Page 6-25
Company Confidential
WCDMA Rx Troubleshooting
No
No
Apply a –48dBm
2141MHz CW signal
from generator to
WCDMA RF connector
Scope probe on RXI/RXQ
lines R844/R845 400mVpp
DC offset 700mV
FET Probe R845/R845
Freq=1MHz
RF Level =-7dBm
No
Y
es
WCDMA RX
Chain OK
Check signal level at SAW
Filter output C844
-45dBm
OK?
Replace
Duplexer
Signal on
balun input
-54dBm
Y
es
Signal on balun
diff output
C890/C892
-57dBm
Replace Balun
Probe on Rx VCO
output 4280MHz
Level ≈ -17dBm
Y
es
No
Replace
SAW Filter
Signal level at output of LNA
C811.
Manual Mode in Phoenix
Low gain=-70dBm
Mid Gain=-55dBm
High gain =-44dBm
No
Check VR4
2.8v
Replace
REX
Y
es
No
Y
es
No
No
Replace C842 and/
or C844
Y
es
Synthesizer
Troubleshooting
Baseband
Troubleshooting
Phoenix Settings:
Rx Contol (WCDMA)
AGC mode =Manual
AFC algorithm=Off
Channel=10700 (2140MHz)
Click SEND
Y
es
Y
es
Phoenix Settings:
Rx Control (WCDMA)
AGC mode = Manual
AFC algorithm = Off
Channel = 10700 (2140MHz)
BB AGC = 33dB
Click SEND