Fig 13 Receiver Fault Chart 2; Fig 14 Receiver Fault Chart 3, 4, 5 - Nokia NPL-4 Series Troubleshooting Instructions

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