Wcdma Tx Troubleshooting; Pa & Dc-Dc Converter Troubleshooting - Nokia 7600 Troubleshooting Manual

CCS Technical Documentation

WCDMA Tx Troubleshooting

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