Nokia 6260 RM-25 Service Manual page 175

Mobile terminal

Table of Contents

RM-25

RF troubleshooting

Introduction to RF troubleshooting.........................................................................................................................................7-5

RF key component placement....................................................................................................................................................7-5

Receiver.............................................................................................................................................................................................7-8

Receiver troubleshooting......................................................................................................................................................7-8

Measuring Rx/IQ signals using RSSI....................................................................................................................................7-9

Measuring RX performance using SNR measurement...............................................................................................7-10

Measuring Rx module manually using oscilloscope and spectrum analyzer (EGSM900)................................7-10

Measuring Rx module manually using oscilloscope and spectrum analyzer (GSM1800)...............................7-13

Measuring Rx module manually using oscilloscope and spectrum analyzer (GSM1900)...............................7-14

RM-25 measurement points in the receiver..................................................................................................................7-17

Calibrating RX Channel Select Filter.................................................................................................................................7-18

Calibrating RX..........................................................................................................................................................................7-19

Transmitter....................................................................................................................................................................................7-22

Introduction to RM-25 transmitter troubleshooting..................................................................................................7-22

Preparing for transmitter troubleshooting...................................................................................................................7-23

Troubleshooting TX-BB interface and control signals................................................................................................7-25

Troubleshooting RF side of transmitter.........................................................................................................................7-27

Introduction to transmitter tuning..................................................................................................................................7-28

Tuning TX/IQ............................................................................................................................................................................7-28

Tuning TX power level..........................................................................................................................................................7-32

Introduction to synthesizer troubleshooting...............................................................................................................7-40

Preparing for synthesizer troubleshooting...................................................................................................................7-42

Measuring the synthesizer manually using spectrum analyzer ............................................................................7-44

Bluetooth........................................................................................................................................................................................7-45

Bluetooth component placement....................................................................................................................................7-45

Bluetooth settings for Phoenix.........................................................................................................................................7-45

Troubleshooting Bluetooth................................................................................................................................................7-47

List of Tables

Table 24 RF retuning after changing a component.............................................................................................................7-6

Table 25 RX calibration settings..............................................................................................................................................7-20

Table 26 Spectrum analyzer settings.....................................................................................................................................7-28

Table 27 RF Control window settings.....................................................................................................................................7-30

Table 28 Spectrum analyzer settings for Tx power level tuning...................................................................................7-33

Table 29 Spectrum analyzer settings for Tx level tuning.................................................................................................7-34

List of Figures

Figure 107 RF key component placement...............................................................................................................................7-6

Figure 108 RF key components (left)........................................................................................................................................7-7

Figure 109 RF key components (right).....................................................................................................................................7-7

Figure 110 Receiver signal paths...............................................................................................................................................7-8

Figure 111 Troubleshooting flowchart for EGSM900.........................................................................................................7-12

Figure 112 Probed Rx I/Q signals J730, J731........................................................................................................................7-13

Figure 113 Troubleshooting flowchart for EGSM1800......................................................................................................7-14

Figure 114 Troubleshooting flowchart for EGSM1900......................................................................................................7-16

Figure 115 Measurement points at RX frontend - part 1.................................................................................................7-17

Figure 116 Measurement points at RX frontend - part 2.................................................................................................7-18

Figure 117 Measurement points at baseband and digital IQs.......................................................................................7-18

9235618 (Issue 2)

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Company Confidential

Nokia Customer Care

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