Audio Troble - LG -E405 Service Manual

4.19 Audio Troble

4.19.1 Receiver Path
MSM7225A EAR1_OP, EAR1_ON -> RCV_P, RCV_N -> R4023, R4021 (TP3) ->
U4001 (PM8029 : PMIC) -> FB4001, FB4000 (TP2) -> CN7000 (TP1) (SPK Pad)
Connect the phone to network
equipment and set-up call.
Set-up 1KHz tone out.
Can you hear the 1KHz TONE?
The sine wave appears at
The sine wave appears at
FB4001, FB4000 (TP2)?
The sine wave appears at
R4023, R4021(TP3)?
Change the U2000 (MSM7225A) or
Change the main PCB
LGE Internal Use Only
START
No
CN7000 (TP1) ?
No
No
No
Yes
END
Yes
Re-contact or Change the SPK/RCV
module
Yes
Change the SPK/RCV module
Yes
Change the U4001 (PMIC)
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4. TROUBLE SHOOTING
Only for training and service purposes