Nokia N72

Table of Contents
Introduction to RF troubleshooting.....................................................................................................................7–5
RF key component placement...............................................................................................................................7–5
Troubleshooting test point locations...................................................................................................................7–7
Receiver troubleshooting......................................................................................................................................7–9
Introduction to Rx troubleshooting................................................................................................................7–9
GSM Rx chain activation for manual measurements / GSM RSSI measurement........................................7–10
Transmitter troubleshooting..............................................................................................................................7–10
General instructions for Tx troubleshooting................................................................................................7–10
Checking antenna functionality.....................................................................................................................7–12
Antenna troubleshooting...............................................................................................................................7–14
RF tunings.............................................................................................................................................................7–14
Introduction to RF tunings.............................................................................................................................7–14
Cable and adapter losses................................................................................................................................7–15
RF autotuning .................................................................................................................................................7–15
RF manual tuning guide.................................................................................................................................7–18
Required manual tunings after component changes.............................................................................7–18
System mode independent manual tunings...........................................................................................7–18
RF channel filter calibration.................................................................................................................7–18
PA (power amplifier) detection...........................................................................................................7–19
Temperature sensor calibration .........................................................................................................7–19
GSM receiver tunings.................................................................................................................................7–20
Rx calibration (GSM)..............................................................................................................................7–20
Rx band filter response compensation (GSM)....................................................................................7–22
Rx AM suppression (GSM)......................................................................................................................7–27
GSM transmitter tunings............................................................................................................................7–29
Tx IQ tuning (GSM).................................................................................................................................7–29
Tx power level tuning (GSM)................................................................................................................7–31
List of Tables
Table 11 RF channel filter calibration tuning limits.........................................................................................7–18
Table 12 Temperature sensor calibration tuning limits..................................................................................7–20
Table 13 RF tuning limits in Rx calibration........................................................................................................7–22
Table 14 RSSI level values....................................................................................................................................7–28
Table 15 Tx IQ tuning limits................................................................................................................................7–30
List of Figures
Figure 57 RF key component placement..............................................................................................................7–6
Figure 58 Test point locations for spectrum analyzer........................................................................................7–7
Figure 59 Test points for oscilloscope - bottom..................................................................................................7–8
Figure 60 Test points for oscilloscope - top.........................................................................................................7–9
Figure 61 RSSI Reading window.........................................................................................................................7–10
Figure 62 RF Controls window............................................................................................................................7–12
Figure 63 Feed and GND spots of the main antenna........................................................................................7–13
Figure 64 BT antenna...........................................................................................................................................7–13
Figure 65 RF channel filter calibration typical values.......................................................................................7–19
RM-180
RF Troubleshooting and Tuning Guide Nokia Customer Care
Issue 1 COMPANY CONFIDENTIAL Page 7 –3
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