5-2
Troubleshooting
Change Board.
YES
YES
Check the MIC.
The level is 2.85V?
MIC is not working.
A few hundreds mV
of signal levels
are measured?
END
NO
NO
Check the signal level at the
point U500 (C607 = 2.2uF).
Check the signal level at the
U604 Pin 5,6.
Check R611 and R612.
Check F602 and R719.
YES
Both PINs of
signal level are 2.0V?
NO
Replace U604.
Case 1
Both is not OK.
Case 2
PIN5 is only OK.
Check R613.
5.2 MIC Trouble
Содержание BD20
Страница 1: ...GSM PHONE SERVICE MANUAL MODEL BD20 1st version 2004 01 27 ...
Страница 2: ...Rev 1 00 ...
Страница 36: ...6 PCB Diagram 6 1 Main PCB 6 1 Top View ...
Страница 37: ...6 2 PCB Diagram Bottom View ...
Страница 46: ...9 Block Diagram 9 1 BB Block Diagram 9 1 ...
Страница 48: ...Block Diagram 9 3 Power Supply Block Diagram 9 3 ...
Страница 49: ...10 Schematic Diagram 10 1 Key Pad 10 1 ...
Страница 50: ...10 2 Schematic Diagram 10 2 Main Board 10 2 1 Chipset ...
Страница 51: ...10 3 Schematic Diagram 10 2 2 Memory Melody ...
Страница 53: ...10 5 Schematic Diagram 10 2 4 Connector ...
Страница 54: ...10 6 Schematic Diagram 10 3 RF Top Schematic 10 3 1 RF Pam ...
Страница 55: ...10 7 Schematic Diagram 10 3 2 RF Main IC ...