Audio Part - Samsung SGH-L770 Service Manual

Flow Chart of Troubleshooting

10-1-2. Audio part

Receiver sound is not heard
Check the speaker soldering part
Check the SPK Amp
input/output signal
R516,R527/L503,L502
Check U302
(VAUDIOA_2.5, VAUDIO_2.5)
OK
Receiver sound from headset
Check the IF con soldered
condition
Check the jack in (R606)
Hi < - > Low
R516,R527/L503,L502
Check the E/P amp input / output
C552, C553 / R641, R642
Check U302
(VAUDIOA_2.5, VAUDIOB_2.5)
OK
SAMSUNG Proprietary-Contents may change without notice
This Document can not be used without Samsung's authorization
NO
Yes
Resoldering
Check U502(VBAT_AUDIO,
AUDIO_SEL, SPK_AMP_EN)
Change the amp
Change U302 and Re-download
Change the board
NO
Yes
Resoldering
Check the headset GND
Check U504 (EARAMP2.5V, EARAMP_
EN)
Change U302
Change the board
10-4