5-13
Troubleshooting
YES
END
NO
YES
NO
NO
Check
TX VCO U202 pin 24:
Frequency = 1747.8 MHz?
Power -12 dBm?
Check for:
• U101 soldering.
• U101 pin 4 VBAT DC voltage (>3.3V).
• U101 pin 3 (C121) PA_ON high voltage.
• U101 pin 2 (Q100 pin 1) BSW high voltage.
• U101 pin 6 (C119) PA_LEVEL signal.
• U101 pin 7 (C107) 1747.8 MHz freq. & power.
Replace U101 if defective.
Check for:
• U100 soldering.
• U100 pin 7 low voltage.
• U100 pin 4 high voltage.
Replace U100 if defective.
Check Power Amp
U101 pin 11 (C115):
Frequency = 1747.8 MHz?
Power 11 dBm?
Check
ANT switch U100 pin 10 (C112):
Frequency = 1747.8 MHz?
Power 9 dBm?
YES
Check for:
• RF connector ANT101 soldering.
• Matching network L100, C108 soldering.
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=
>
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Check for:
• U202 soldering.
• U202 pin 14, 23, 26, 32 (DC 2.85V)
Replace U202 if defective.
B
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 ...