Trouble Shooting; Baseband Part Troubleshooting - LG F1200 Service Manual

4. TROUBLE SHOOTING

4. TROUBLE SHOOTING

4.1 Baseband Part Troubleshooting

(1) Power-On Trouble
• Power-On Sequence
- Connecting Battery
- Power-On Key Detection
- PWON signal goes to ABB and then ABB resets DBB by ONNOFF signal
- ONNOFF turns low (0V) to High (2.8V) and it resets DBB (Calypso plus)
- All LDOs (internal LDOs of ABB and external LDOs) are turned on
• Check Points
- Battery Voltage
- Power-On Key Detection (PWON signal)
- Output of LDOs
• Trouble Shooting Setup
- Connect PIF-UNION Jig to the phone
- Set the TI-Remote switch at PIF-UNION Jig off
• Trouble Shooting Procedure
- Check Battery Voltage
- END Key Dome switch condition
- Check the output voltage of all LDOs
(2) Charging Trouble
• Charging method : CC-CV
• Charger Detection Voltage : Over 4.0V
• Charging Time : About 3Hours
• Charging Current : 550mA
• Cut-off Current : 80mA
• Low Battery Alarm
- Talk mode : 3.62V
- Standby mode : 3.50V
• Switch-Off Voltage
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