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5-13
Troubleshooting
YES
YES
NO
YES
YES
NO
NO
Check
TX VCO U202 pin 25
frequency & power.
Frequency = 902.4 MHz
Power -6dBm?
Check :
• RF connector Ant101 soldering.
• Matching network L100, L101, C105 soldering.
• Resolder if defective.
Check :
• U202 soldering
• U202 pin 26 = DC 2.85.
Replace U202 if defective.
Check :
• U101 soldering
• U101 pin 4 VBAT DC voltage (>3.3V)
• U101 pin 3 PAON high voltage
• U101 pin 2 BSW low voltage
• U101 pin 6 PA_LEVEL signal
• U101 pin 7 902.4MHz freq & power
Replace U101 if defective.
Check :
• U110 soldering
• U110 pin 2 high voltage
• U110 pin 11 low voltage
Replace U110 if defective.
Check
Power Amp Output C106
frequency & power.
Frequency = 902.4MHz
Power 16dBm?
Check
ANT switch U110 pin 8
frequency & power.
Frequency = 902.4MHz
Power 15dBm?
END
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Summary of Contents for GSM ST11
Page 1: ...GSM PHONE SERVICE MANUAL MODEL ST11 ...
Page 2: ...Rev 1 00 ...
Page 6: ...1 2 Introduction Memo ...
Page 15: ...3 4 Exploded View and Parts List 3 4 1 Exploded View 3 5 ...
Page 41: ...Troubleshooting Memo 5 20 ...
Page 42: ...6 Block Diagram 6 1 BB Block Diagram 6 1 ...
Page 43: ...6 2 Block Diagram 6 2 RF Block Diagram ...
Page 51: ...7 8 Schematic Diagram Memo ...
Page 52: ...8 PCB Diagram 8 1 Main PCB 8 1 Top View ...
Page 53: ...8 2 PCB Diagram Bottom View ...