User Guide

Draft 01 Page 3
NHM-4 Disassembly Instructions.................................................................................. 5
Phone disassembly steps ..............................................................................................5
Reassembly ................................................................................................................19
Bluetooth module removal and reassembly ...............................................................20
Transceiver Troubleshooting ....................................................................................... 25
Test points ..................................................................................................................25
SIM test points ........................................................................................................ 25
Bluetooth test points................................................................................................ 26
Power test points ..................................................................................................... 28
LCD, RF and Flash test points ................................................................................ 29
Miscellaneous test points ........................................................................................ 31
Flash programming and RF power supply test points............................................. 32
Troubleshooting steps .................................................................................................. 35
Main troubleshooting tree, 1 ......................................................................................36
Main troubleshooting tree, 2 ......................................................................................37
Main troubleshooting tree, 3 ......................................................................................38
Keypad troubleshooting 2 ..........................................................................................55
RF Troubleshooting ..................................................................................................... 59
Introduction ................................................................................................................59
Transmitter .................................................................................................................59
Transmitter troubleshooting diagram...................................................................... 61
Hagar troubleshooting............................................................................................. 62
PA & Antenna switch troubleshooting.................................................................... 63
Transmitter signals.................................................................................................. 64
Receiver................................................................................................................... 65
Receiver troubleshooting diagram for GSM900..................................................... 67
Receiver troubleshooting diagram for GSM1800................................................... 68
LNA gangster checking GSM900 & GSM1800 ..................................................... 69
Synthesizer .............................................................................................................. 70
Synthesizer troubleshooting diagram...................................................................... 71
Synthesizer signals .................................................................................................. 72