
CCS Technical Documentation
Troubleshooting Instructions
NSB-9
Issue 1 04/03
Nokia Corporation
Page 13
Figure 3: Fault finding chart, RX850
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 RX signal at
antenna switch output
TP63
881.667 MHz
9
8
Change antenna
switch Z500
Check RX signal at
dual filter output TP64
881.667 MHz
9
8
Change dual filter
Z520
Check LNA voltages
at TP65 1 VDC
TP67 2.6 VDC
Check RX signal at
LNA output TP66
881.667 MHz
9
8
8
9
Check LNA V500 and
other components
around it
If R501 and R502 are
ok, change Hagar
ASIC N600
Check RX signal at
filter output TP68
881.667 MHz
9
Change filter Z501
8
Apply input signal
881.667 MHz
-50 dBm
9
Change VCTCXO
G660
9
DMM
OSC
DMM
SA
SA
SA
DMM
SA