77
Checking Flow
Start
NO
YES
Replace U101(EGV) or Change another
Ear-Mic set and Try again .
Does the audio profile
of the phone change to
the earphone mode ?
NO
YES
Re-solder or replace the
component
Check voltage level of
TP6 VMIC = 2.5V?
Re-solder causal
component(J501)
Check component
status around VMIC
NO
YES
Earphone
Check the signal level and
HS_MIC . Is it about
1.2~1.5VDC with a few
tens mV AC ?
Check U101(EGV)
NO
YES
YES
MIC
Summary of Contents for GB108
Page 1: ...1 GB108 Service Manual LG Electronics ...
Page 11: ...11 3 TECHNICAL BRIEF Digital Main Processor Figure 3 1 PMB7880 FUNCTIONAL BLOCK DIAGRAM ...
Page 12: ...12 ...
Page 22: ...22 RTC 32 768KHz Crystal Figure 3 4 E GoldVoice RTC Interface ...
Page 24: ...24 ...
Page 25: ...25 3 6 SIM Card Interface Figure 3 6 SIM CARD Interface ...
Page 26: ...26 3 7 KEYPAD Interface Figure 3 7 KEY MAXTRIX Interface ...
Page 27: ...27 3 8 Battery Charging Block Interface Figure 3 8 Charging IC Interface ...
Page 28: ...28 3 9 RF Interface Figure 3 9 RF Module SAW Filter Interface ...
Page 29: ...29 ...
Page 30: ...30 3 10 Audio Interface Figure 3 10 1 Audio Interface ...
Page 31: ...31 ...
Page 32: ...32 Figure 3 10 2 Main Speaker Receiver Interface ...
Page 33: ...33 Figure 3 10 3 Main Microphone Interface Figure 3 10 4 Headset Interface ...
Page 36: ...36 3 13 Memory Interface Figure 3 13 Memory Interface ...
Page 39: ...39 3 15 FM Radio Interface GB105a b GB106 GB107a b GB108 only Figure 3 15 FM Radio Interface ...
Page 41: ...41 ...
Page 42: ...42 PAM Matching component Mobile SW Antenna Matching component Antenna connect point ...
Page 43: ...43 ...
Page 44: ...44 ...
Page 45: ...45 ...
Page 46: ...46 ...
Page 47: ...47 ...
Page 48: ...48 TP2 TP1 TP3 ...
Page 49: ...49 TP2 TP1 TP3 ...
Page 50: ...50 ...
Page 52: ...52 Circuit Diagram TP5 TP6 TP1 TP3 TP4 TP2 ...
Page 54: ...54 4 4 SIM Card Trouble Test Point Circuit Diagram ...
Page 56: ...56 4 5 Vibrator Trouble Test Point Circuit Diagram ...
Page 58: ...58 4 6 Keypad Trouble Test Point Circuit Diagram ...
Page 59: ...59 Checking Flow Change Metal Dome Check Metal Dome Start Change PCB NG OK ...
Page 60: ...60 4 7 RTC Trouble Test Point Circuit Diagram ...
Page 62: ...62 4 8 Key Backlight Trouble Test Point ...
Page 63: ...63 Circuit Diagram ...
Page 65: ...65 4 9 LCM Backlight Trouble Test Point Circuit Diagram ...
Page 67: ...67 4 10 LCM Trouble Test Point Circuit Diagram ...
Page 69: ...69 4 11 Microphone Trouble Test Point Circuit Diagram ...
Page 71: ...71 4 12 Receiver Trouble Test Point Circuit Diagram ...
Page 73: ...73 4 13 Speaker Trouble Test Point Circuit Diagram TP6 TP5 TP2 TP3 TP4 TP1 ...
Page 75: ...75 4 14 Headphone Trouble Test Point ...
Page 76: ...76 Circuit Diagram TP1 TP2 ...
Page 79: ...79 4 15 Charging Trouble Test Point Circuit Diagram ...
Page 81: ...81 4 16 FM Radio Trouble GB105a b GB106 GB107a b only Test Point ...
Page 82: ...82 Circuit Diagram ...
Page 86: ...86 5 DOWNLOAD 5 1 Download Setup ...
Page 91: ...91 6 BLOCK DIAGRAM ...
Page 92: ...92 ...
Page 93: ...93 ...
Page 94: ...94 ...
Page 95: ...95 ...
Page 96: ...96 ...
Page 97: ...97 ...
Page 99: ...99 BGA PIN Check of Memory Top View Use U201 Memory S71GL032N40BFW0P Not Use EUSY0328002 ...
Page 100: ...100 9 PCB LAYOUT ...
Page 105: ...105 11 Calibration 11 1 Test equipment setup 11 2 Calibration Steps Execute HK_36 exe ...
Page 107: ...107 Select MODEL Click START for RF calibration RF Calibration finish ...
Page 113: ...113 13 EXPLODED VIEW REPLACEMENT PART LIST 13 1 Exploded View GB108 ...
Page 114: ...114 ...