NSB-9
Troubleshooting Instructions
CCS Technical Documentation
Page 10
Nokia Corporation
Issue 1 04/03
Figure 2: Fault finding chart, TX1900
Check VCTCXO
output signal at TP20
26 MHz
Check VCTCXO
supply voltage at TP3
2.78 VDC
±
3%
9
8
Check VCTCXO
control voltage at
TP13
1.1 VDC
±
200 mV
8
9
Start baseband
troubleshooting (UEM)
8
Start baseband
troubleshooting (UEM)
Check TX IQ signals
at TP21
9
8
Start baseband
troubleshooting (UEM)
Check TX modulator
output signal at TP22
1880 MHz
9
8
Check Hagar ASIC
supply voltages at
TP4, TP5, TP6, TP8:
2.78 VDC
±
3%
TP10: 1.35 VDC
±
2%
TP1: 4.75 VDC
±
3.2%
8
Start baseband
troubleshooting (UEM)
9
Check SHF VCO
output signal at TP40
3760 MHz
8
Check VCO supply
voltage at TP7:
2.78 VDC
±
3%
9
8
9
Check VCO control
voltage at TP41:
2.7 VDC
±
200 mV
Change
Hagar ASIC
N600
Change
SHF VCO
G650
Change VCTCXO
G660
9
DMM
OSC
DMM
OSC
SA
SA
DMM
DMM
DMM
8
9
8