LG C3400 Service Manual page 69

4. Troubleshooting
Checking Flow
SETTING : Enter the engineering mode, and set vibrator on at vibration of BB test menu
START
Is the voltage at pin 3
of Q300 high ?
YES
Is the voltage at pin 2
of Q300 low ?
YES
Is the voltage at pin 1
of Q300 high ?
YES
Check the soldering
of CN601 ?
YES
Check the soldering
of vibrator ?
YES
Replace vrbrator
YES
Vibrator
working
NO
Check the soldering
of R353, R354
YES
NO
Check the soldering
YES
NO
Check the soldering
YES
Replace Q300
NO
NO
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NO
Resolder R353, R354
NO
of R351
Resolder R351
NO
of R350
Resolder R350
Resolder CN601
Resolder vibrator