Nokia 5140 Manuales De Servicio
Nokia Customer Care
Troubleshooting Instructions
Company confidential
NPL-4/5
Issue 1 05/04
Copyright © 2004 Nokia Corporation. All rights reserved.
Page 25
Figure 17: Receiver Fault Chart 8
Figure 18: Receiver Fault Chart 9
Rx signal paths
Antenna switch (RX/TX switch)
RF signal is fed directly from the antenna-pad (J908) to the antenna switch (Z809).
This switch has the function of a diplexer, which consists of two combined paths (low
pass/high pass filter combination), a GSM850/900 and a GSM1800/1900 path. The GSM
850/900 input signals pass the switch to the Rx1 output. Via a switch the GSM 1800
input signals pass to Rx2 output and GSM 1900 to Rx3 output, depending on the control
pass/high pass filter combination), a GSM850/900 and a GSM1800/1900 path. The GSM
850/900 input signals pass the switch to the Rx1 output. Via a switch the GSM 1800
input signals pass to Rx2 output and GSM 1900 to Rx3 output, depending on the control
Spectrum Analyzer:
1)
Center Freq:
calculated from Phoenix
RBW 20kHz
Change Rx SAW
(Z806, Z807, Z808)
depending on selected band
(Z806, Z807, Z808)
depending on selected band
No
Yes
Note
1)
:
RF levels are dependent on RF probe and have to be validated
with a known good sample.
with a known good sample.
Receiver
Fault Chart 8.
Fault Chart 8.
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
Check Rx SAW filter of selected band:
GSM850/900
Z808
output both lines > -80dBm
GSM1800 Z807
output both lines > -80dBm
GSM1900 Z806
single output > -74dBm
Note! 1) RF levels are dependent on RF probe
and have to validated with a known good sample.
and have to validated with a known good sample.
No
Check supply
filter components
around V802 and
RF ASIC N500
filter components
around V802 and
RF ASIC N500
If selected band = GSM1900
Oscilloscope:
Check voltages for V802:
Check voltages for V802:
Voltage at C827 = 2.6V
Voltage at C801 = 0V
Voltage at C801 = 0V
Yes
Change V802
Spectrum Analyzer:
1)
Check external LNA V802:
Output signal pin 3 > - 56dBm
Output signal pin 3 > - 56dBm
No
Receiver
Fault Chart 9.
Fault Chart 9.
Note
1)
:
RF levels are dependent on RF probe and have to be validated
with a known good sample.
with a known good sample.
RF ASIC N500 seems to be
defective. Exchange N500.
defective. Exchange N500.
No
Spectrum Analyzer:
1)
Check balun T801:
Both output signals at pin 3+4 > - 62dBm
Both output signals at pin 3+4 > - 62dBm
No
Yes
No
Yes
Yes
Change T801
Note! 1) RF levels are dependent on RF probe
and have to validated with a known good sample.
and have to validated with a known good sample.