User Guide

Nokia Customer Care Troubleshooting Instructions
Company confidential NPL-4/5
Issue 1 05/04 Copyright © 2004 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.
Ye s
Note! 1) RF levels are dependent on RF probe
and have to be validated with a known good
sample.