Nokia 7600 - WCDMA Tx Troubleshooting; PA & DC-DC Converter Troubleshooting

CCS Technical Documentation 6-Troubleshooting
Company Confidential NMM-3
Issue 1 (11/2003) Copyright  2003 Nokia Corporation Page 6-23
Company Confidential
WCDMA Tx Troubleshooting
WCDMA Measurement settings:
RBW=30khz VBW=300khz, detector:sample,
CSP=5MHz,CBW=3.84MHz
RFProbe with 10:1 attenuator
Y
es
Y
es
No
No
No
No
No
Check o/p signal level
From RF connector
21dBm @ 1950MHz
TX Signal Found?
Check WCDMA Tx
balanced filter input
(L959)
-4dBm
Synthesizer
Troubleshooting
Tx
OK
Replace
Filter
No
Y
es
Y
es
Check with RF probe
level at PA Input
(C984)
-3dBm
Y
es
PA and DC-DC
Converter
Troubleshooting
Y
es
Check output signal on
500MHz Span signal
found on incorrect
frequency?
Check WCDMA Hex
balanced filter input
(R955 pads)
=-17dBm
Check TXA2 Volt drop
across R906.
DAC=800
V
≈ 80mV
Baseband
Troubleshooting
Check DC conditions
On Hex.
V
CCTC=VPLUS=
V
CCOUT =VCCBIAS
=2.8v
Check components
around Hex
OK?
Replace
faulty
com
p
onents
Replace
HEX
No
Y
es
Y
es
No
Y
es
Tx
OK
Phoenix Settings:
Tx Contol (WCDMA)
Algorithm mode
Start Level =21dBm
Channel=9750 (1950MHz)
Click SEND