Audio Trouble - LG CT815 Service Manual

4.10 Audio trouble

4.10.1 Receiver path
Voice Receiver path as below:
MSM720A Ear_ON/Ear_OP
Connect the phone to network
Equipment and setup call
Hear the tone to the receiver?
at Speaker Sold er pads ?
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Only for training and service purposes
→
U503 (Audio Subsystem)
Start
Setup 1KHz tone out
NO
Change t he Receiver
The sine wave appear
at C514, C515?
YES
The sine wave appear
Can you hear the tone?
YES
END
4. TROUBLE SHOOTING
→
Speaker solder PAD
YES
NO
Change the Main board
NO
Check t he U503
- 111 -
→
Speaker
END
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