Baseband Part Troubleshooting; Power On Trouble - LG KE590 Service Manual

4.4 Baseband Part Troubleshooting

4.4.1 Power On Trouble

4.4.1.1 Power-On Trouble Troubleshooting
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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 (Neptune)
- All LDOs (internal LDOs of ABB and external LDOs) are turned on
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Check Points
- Battery Voltage
- Power-On Key Detection (Pwon signal)
- Output of LDOs
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Trouble Shooting Setup
- Connect PIF-UNION to the phone.
- Set the TI-remote switch at PIF-UNION off.
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Trouble Shooting Procedure
- Check Battery Voltage
- END_KEY Dome Switch condition& Side FPCB conditon
- Check the output voltages of all LDOs.
CN203
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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VA210
4. TROUBLE SHOOTING
R211
R210
VA209
VA211
EVLC5S02100
<Fig. 1>
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KBC(2)
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PWON
LGE Internal Use Only