Nokia 1650, Service Manual, Page: 50 / 109

Table of Contents
General RF troubleshooting .................................................................................................................................. 5–5
General RF troubleshooting ............................................................................................................................. 5–5
RF key components ........................................................................................................................................... 5–5
Auto tuning ............................................................................................................................................................. 5–7
Receiver GSM900/1800 .......................................................................................................................................... 5–9
General instructions for GSM900 RX troubleshooting ................................................................................... 5–9
Troubleshooting diagram for GSM 900 receiver ......................................................................................... 5–11
General instructions for GSM 1800 RX troubleshooting ............................................................................. 5–12
Troubleshooting diagram for GSM 1800 receiver ....................................................................................... 5–13
Measurement points in the receiver ............................................................................................................ 5–14
Receiver GSM850/1900 ....................................................................................................................................... 5–14
General instructions for GSM 850 RX troubleshooting ............................................................................... 5–14
Troubleshooting diagram for GSM 850 receiver ......................................................................................... 5–16
General instructions for GSM1900 RX troubleshooting .............................................................................. 5–17
Troubleshooting diagram for GSM 1900 receiver ....................................................................................... 5–18
Measurement points in the receiver ............................................................................................................ 5–19
Transmitter GSM900/1800 .................................................................................................................................. 5–19
General instructions for GSM 900 TX troubleshooting ................................................................................ 5–19
Troubleshooting diagram for GSM 900 transmitter ................................................................................... 5–21
GSM900 TX output power .............................................................................................................................. 5–22
General instructions for GSM1800 TX troubleshooting .............................................................................. 5–25
Troubleshooting diagram for GSM 1800 transmitter ................................................................................. 5–26
GSM1800 TX output power ............................................................................................................................ 5–26
Transmitter GSM850/1900 .................................................................................................................................. 5–30
General instructions for GSM 850 TX troubleshooting ................................................................................ 5–30
Troubleshooting diagram for GSM 850 transmitter ................................................................................... 5–32
GSM850 TX output power .............................................................................................................................. 5–33
General instructions for GSM1900 TX troubleshooting .............................................................................. 5–36
Troubleshooting diagram for GSM 1900 transmitter ................................................................................. 5–37
GSM1900 TX output power ............................................................................................................................ 5–37
Crystal troubleshooting ..................................................................................................................................... 5–41
Introduction .................................................................................................................................................... 5–41
FM radio troubleshooting ................................................................................................................................... 5–41
FM radio troubleshooting .............................................................................................................................. 5–41
FM radio troubleshooting diagram .............................................................................................................. 5–43
List of Figures
Figure 30 RF key components on PWB ................................................................................................................. 5–5
Figure 31 Test points on FM module .................................................................................................................... 5–6
Figure 32 Supply and control points at FEM (N7100) and Litti (D2901) ............................................................ 5–7
Figure 33 Auto tuning concept with CMU200 ...................................................................................................... 5–8
Figure 34 Auto tuning concept with RX and TX tuning devices and splitter .................................................... 5–8
Figure 35 GSM900 RF controls window ............................................................................................................. 5–10
Figure 36 GSM 900 Receiver troubleshooting ................................................................................................... 5–11
Figure 37 GSM1800 RF controls window ........................................................................................................... 5–12
Figure 38 GSM 1800 Receiver troubleshooting ................................................................................................ 5–13
Figure 39 Measurement points at the RX SAW Filters – Z7101/Z7100 ........................................................... 5–14
Figure 40 GSM850 RF controls window ............................................................................................................. 5–15
Figure 41 GSM 850 Receiver troubleshooting ................................................................................................... 5–16
RM-305; RM-306
RF troubleshooting
Issue 2 COMPANY CONFIDENTIAL Page 5 –3
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