Nokia 7600 - WCDMA Tx Synthesizer Troubleshooting

CCS Technical Documentation 6-Troubleshooting
Company Confidential NMM-3
Issue 1 (11/2003) Copyright  2003 Nokia Corporation Page 6-27
Company Confidential
WCDMA Tx Synthesizer Troubleshooting
Replace
VCO
Synth
OK
Probe VCO o/p
3900Mhz
Span 1MHz
RF Level= -17dBm
V
CO o/p signal
<-17dBm?
Check o/p signal on 1GHz
Span. Signal found on
correct frequency?
Check with meter VCO
control voltage R914=
0V?
VCO control
Voltage >4V
Check balun output
& VCO solder joints
OK?
Replace
VCO
Check
V
cc= 2.8v
ExtReg1
Baseband
Troubleshooting
Check VCO loop
filter components
OK?
Replace faulty
components
Check synth serial
interface on Tex
Tex
Troubleshooting
Replace faulty
components
Replace
VCO
Replace
VCO
Y
es
Y
es
Y
es
Y
es
Y
es
No
Y
es
Y
es
No
No
No
No
No
No
No
Y
es
Y
es
Phoenix Settings:
Tx Contol (WCDMA)
Algorithm mode
Start Level = 0dBm
Channel= 9750 (1950MHz)
Click SEND