Nokia 6720 classic, Service Manual

Page: 135 / 216

Table of Contents
General RF troubleshooting .................................................................................................................................. 4–5
Introduction to RF troubleshooting ................................................................................................................ 4–5
RF key components ........................................................................................................................................... 4–6
Auto tuning ............................................................................................................................................................. 4–7
Introduction to auto tuning ............................................................................................................................. 4–7
Auto tuning procedure ..................................................................................................................................... 4–7
Self test troubleshooting ....................................................................................................................................... 4–8
Phoenix self test troubleshooting ................................................................................................................... 4–8
Receiver troubleshooting ................................................................................................................................... 4–10
Introduction to receiver (RX) troubleshooting ............................................................................................ 4–10
GSM RX chain activation for manual measurements/GSM RSSI measurement ........................................ 4–10
GSM receiver troubleshooting flowchart ..................................................................................................... 4–11
WCDMA RX chain activation for manual measurement .............................................................................. 4–12
WCDMA RSSI measurement ........................................................................................................................... 4–13
WCDMA receiver troubleshooting flowchart ................................................................................................ 4–14
Transmitter troubleshooting ............................................................................................................................. 4–15
Introduction to transmitter (TX) troubleshooting ...................................................................................... 4–15
GSM transmitter troubleshooting ................................................................................................................. 4–15
GSM transmitter troubleshooting flowchart ............................................................................................... 4–19
WCDMA transmitter troubleshooting ........................................................................................................... 4–19
WCDMA transmitter troubleshooting flowchart .......................................................................................... 4–23
Troubleshooting with RF-shield removed ........................................................................................................ 4–24
Introduction .................................................................................................................................................... 4–24
Voltage checking ............................................................................................................................................ 4–24
VCTCXO troubleshooting ................................................................................................................................ 4–27
RF component reference ............................................................................................................................... 4–27
Antenna ................................................................................................................................................................ 4–30
Antenna overview .......................................................................................................................................... 4–30
Main antenna functionality ........................................................................................................................... 4–30
Antenna troubleshooting .............................................................................................................................. 4–30
List of Figures
Figure 35 RF key components ............................................................................................................................... 4–6
Figure 36 Auto tuning concept with CMU200 ...................................................................................................... 4–7
Figure 37 Phoenix RSSI Reading window ......................................................................................................... 4–10
Figure 38 Phoenix Rx Control window with sample settings (WCDMA band I) ............................................. 4–12
Figure 39 Phoenix Rx Power Measurement window ....................................................................................... 4–13
Figure 40 Phoenix RF Controls window ............................................................................................................ 4–15
Figure 41 Typical readings ................................................................................................................................. 4–17
Figure 42 Phoenix WCDMA Tx control window ................................................................................................ 4–20
Figure 43 Typical readings ................................................................................................................................. 4–22
Figure 44 Phoenix WCDMA Tx Control window settings .................................................................................. 4–25
Figure 45 Test points for voltage checking ...................................................................................................... 4–26
Figure 46 Component reference schematics .................................................................................................... 4–29
Figure 47 Main antenna ...................................................................................................................................... 4–30
Figure 48 Antenna contacts ............................................................................................................................... 4–31
RM-424; RM-564
RF Troubleshooting
Issue 1 COMPANY CONFIDENTIAL Page 4 –3
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