Nokia 7600 - 1. Your phone; Keys and connectors

NMM-3 Company Confidential
6-Troubleshooting CCS Technical Documentation
Page 6-22 Copyright  2003 Nokia Corporation Issue 1 (11/2003)
Company Confidential
GSM900/1800 Synthesizer Troubleshooting
Synth
OK
Probe VCO o/p
3769.6MHz GSM900
3685.6MHz GSM1800
Span 1MHz
RF Level=-10dBm
V
CO output signal
<-10dBm?
Check output signal on
1GHz Span. Signal found
on correct frequency?
Check with meter VCO
control voltage
V
c=0V?
Check Balun output
& VCO solder joints
OK?
Replace
V
CO
Check VCO
V
cc=2.8v
Baseband
Troubleshootin
g
Check VCO loop
filter components
OK?
Replace faulty
components
Check synth serial
Interface on Helgo
Helgo
Troubleshooting
Replace faulty
components
Replace
V
CO
Replace
V
CO
Y
es
Y
es
Y
es
Y
es
Y
es
No
Y
es
Replace
V
CO
V
CO control
voltage>4V
Y
es
No
No
No
No
No
No
No
Y
es
Y
es
Pheonix Settings:
Band:GSM900/1800
Active unit:RX
Op Mode:Continuous
Rx Chan:37/700
AGC:maximum (default)
Y
es