Nokia 3230 - Smartphone 6 MB, Service Manual, Page: 167 / 276

Table of Contents
Introduction to RF troubleshooting ......................................................................................................................................... 7–5
RF key components ........................................................................................................................................................................ 7–5
Receiver ............................................................................................................................................................................................. 7–7
Receiver troubleshooting ...................................................................................................................................................... 7–7
Measuring Rx/IQ signals using RSSI .................................................................................................................................... 7–8
Measuring RX performance using SNR measurement .................................................................................................. 7–9
Measuring Rx module manually using oscilloscope and spectrum analyzer (EGSM900) ................................ 7–10
Measuring Rx module manually using oscilloscope and spectrum analyzer (GSM1800) ............................... 7–12
Measuring Rx module manually using oscilloscope and spectrum analyzer (GSM1900) ............................... 7–13
Measurement points in the receiver ................................................................................................................................ 7–16
Calibrating RX .......................................................................................................................................................................... 7–17
Compensating RX band filter response ........................................................................................................................... 7–19
Calibrating RX Channel Select Filter ................................................................................................................................. 7–20
Transmitter .................................................................................................................................................................................... 7–21
Introduction to transmitter troubleshooting ............................................................................................................... 7–21
Preparing for transmitter troubleshooting ................................................................................................................... 7–22
Troubleshooting TX-BB interface and control signals ................................................................................................ 7–24
Troubleshooting RF side of transmitter ......................................................................................................................... 7–26
Introduction to transmitter tuning .................................................................................................................................. 7–27
Tuning TX/IQ ............................................................................................................................................................................ 7–27
Tuning TX power level .......................................................................................................................................................... 7–31
Introduction to synthesizer troubleshooting ............................................................................................................... 7–38
Preparing for synthesizer troubleshooting ................................................................................................................... 7–39
Measuring the synthesizer manually using spectrum analyzer ............................................................................ 7–41
Bluetooth ........................................................................................................................................................................................ 7–42
Bluetooth component placement .................................................................................................................................... 7–42
Bluetooth settings for Phoenix ......................................................................................................................................... 7–42
Troubleshooting Bluetooth ................................................................................................................................................ 7–44
List of Tables
Table 7 RF retuning after changing a component ................................................................................................................ 7–6
Table 8 Spectrum analyzer settings ........................................................................................................................................ 7–27
Table 9 RF Control window settings ....................................................................................................................................... 7–29
Table 10 Spectrum analyzer settings for Tx power level tuning ................................................................................... 7–32
Table 11 Power level targets .................................................................................................................................................... 7–33
List of Figures
Figure 118 RF key components ................................................................................................................................................... 7–6
Figure 119 RF key components (left) ........................................................................................................................................ 7–7
Figure 120 RF key components (right) ..................................................................................................................................... 7–7
Figure 121 Receiver signal paths ............................................................................................................................................... 7–7
Figure 122 Troubleshooting flowchart for EGSM900 ......................................................................................................... 7–11
Figure 123 Probed Rx I/Q signals J730, J731 ........................................................................................................................ 7–12
Figure 124 Troubleshooting flowchart for EGSM1800 ...................................................................................................... 7–13
Figure 125 Troubleshooting flowchart for EGSM1900 ...................................................................................................... 7–15
Figure 126 Measurement points at RX frontend - part 1 ................................................................................................. 7–16
Figure 127 Measurement points at RX frontend - part 2 ................................................................................................. 7–16
Figure 128 Measurement points at baseband and digital IQs ....................................................................................... 7–17
RM-51
RF troubleshooting
Nokia Customer Care
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