3155/3155i (RM-41), 3152 (RM-61)
RF Description and Troubleshooting
Page 2 ©2005 Nokia Corporation Company Confidential ISSUE 1 07/2005
Contents Page
Mobile Terminal Components ..................................................................................................................... 5
Main PWB ......................................................................................................................................................5
Preliminary RF Troubleshooting.................................................................................................................. 8
Mobile Terminal Cannot Make a Call ....................................................................................................8
Tx Power Low ................................................................................................................................................8
Transmitter RF Troubleshooting ................................................................................................................. 9
Transmitter Block Diagram .....................................................................................................................10
Transmitter Schematics ...........................................................................................................................11
Transmitter Troubleshooting Setup ......................................................................................................13
AMPS Tx Setup ....................................................................................................................................... 13
Cell Tx Setup ........................................................................................................................................... 16
PCS Setup................................................................................................................................................. 18
Transmitter RF Troubleshooting Procedures ......................................................................................20
Failed Test: Tx PA Detector ................................................................................................................. 21
Tx Output Spectrum.............................................................................................................................. 22
Tx DC Test Points - Bottom Side ....................................................................................................... 23
Tx RF Test Points - Bottom Side........................................................................................................ 24
RF Power Supply DC Test Points - Bottom Side............................................................................ 25
Receiver RF Troubleshooting .................................................................................................................... 27
Receiver Block Diagram ...........................................................................................................................28
Receiver Schematics .................................................................................................................................29
RF AGC Status ............................................................................................................................................31
Turning on the Rx Path ............................................................................................................................32
Switching the Rx Gain States ................................................................................................................34
Checking AMPS from RF to IQ ........................................................................................................... 34
Checking Cell Receiver from RF to IQ.............................................................................................. 35
Checking PCS Receiver from RF to IQ.............................................................................................. 37
Receiver Diagnostic Signal Tracing ......................................................................................................38
Receiver DC Test Points........................................................................................................................ 39
Receiver RF Test Points ........................................................................................................................ 40
Receiver IF Test Points.......................................................................................................................... 41
Receiver Logic Input Voltages ................................................................................................................42
N7160 Receiver Overview .......................................................................................................................43
Synthesizer Troubleshooting .................................................................................................................... 45
Synthesizer Block Diagram .....................................................................................................................46
Synthesizer Schematics ...........................................................................................................................47
Synthesizer Troubleshooting Setup ......................................................................................................48
Incorrect PLL Frequencies.................................................................................................................... 48
VCTCXO Manual Tuning....................................................................................................................... 50
AFC Voltage Troubleshooting .................................................................................................................51
UHF Synthesizer .........................................................................................................................................52
UHF Synthesizer Test Points ............................................................................................................... 53
Rx VHF LO (N7100) Schematic ..............................................................................................................54
Rx VHF LO Troubleshooting ....................................................................................................................55
Tx UHF LO (N7000) Schematic ..............................................................................................................56
Tx UHF LO (N7000) Troubleshooting ....................................................................................................57
GPS Troubleshooting................................................................................................................................... 58
