LG C1100 Service Manual page 69

4. Trouble Shooting
Checking Flow
SETTING : Connect PIF to the phone, and Power on. Enter the engineering mode, and set
Voltage across C408
Check the signal level of
R407, R409
The voltage
of R415 is ~2.8V
Check the state of contact of
dual mode speaker
"Melody on" at Buzzer of BB test menu.
START
No
= 3.3 V?
Yes
No
Yes
No
Yes
No
Yes
Speaker
Working!!
Check the soldering of
R410
Yes
Re-soldering
R410
Check the soldering of
U402
Yes
Re-soldering
U402
- 68 -
No
Replace U102
( ABB LDO)
Replace U401
No
Replace U402
Replace speaker