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Nokia Customer Care
Troubleshooting Instructions
Company confidential
NPL-4/5/
Issue 2 05/05
Copyright
© 2005
Nokia Corporation. All rights reserved.
Page 23
Figure 13: Receiver Fault Chart 2
Figure 14: Receiver Fault Chart 3, 4, 5
Continue with single
band fault finding.
Yes
Are all 3 bands defective?
No
Receiver
Fault Chart 2.
No
Check supply filter
components (C297, C554)
and UEM
Oscilloscope:
Check supply voltages of RF ASIC:
VR4 = 2.8V
Yes
Oscilloscope:
Check supply voltages of RF ASIC:
VR6 = 2.8V
Yes
No
Check supply filter
components (C225, C555)
and UEM
Receiver
Fault Chart 3.
No
Check supply filter
components (R525, C549)
Oscilloscope:
Check reference voltages of RF part:
VrefRF01 = 1.4V
Yes
Oscilloscope:
Check reference voltages of RF part:
VrefRF02 = 1.4V
Yes
No
Check supply filter
components (R421, R423,
C421, C422) and UEM
Receiver
Fault Chart 4.
Spectrum Analyzer:
1)
Check Rx/Tx Switch (Diplexer)
Depending on selected band, check
GSM850/900 output
Rx1
GSM1800 output
Rx2
GSM1900 output
Rx3
Level at Z809 output > -75dBm
Yes
Change Z809
No
Note
1)
:
RF levels are dependent on RF probe and have to be validated
with a known good sample.
Signal Generator:
Level:
–55dBm
Frequency:
calculated from Phoenix
no
offset
Phoenix:
Phone:
local mode
RF Controls
:
Active Unit:
Rx
Op. Mode:
Continuous
Rx/Tx channel:
default (mid)
AGC: 12
Receiver
Fault Chart 5.
Yes
Note! 1) RF levels are dependent on RF probe
and have to be validated with a known good
sample.