Only For Training And Service Purposes - LG KG280 Service Manual

4. TROUBLE SHOOTING
CHECKING FLOW
START
Connect the earphone to the phone
Does the audio
profile of the phone
change to the
earphone mode?
YES
Set the audio part of the test
Equipment to echo mode
Can you hear your
voice from
the earphone?
YES
Earphone will work properly
LGE Internal Use Only
NO
Is the level at pin8
Of CN300 low?
YES
Re-download software
(DBB does not detect the earphone
Change the earphone And try again
NO
Can you hear your voice from
the earphone?
YES
Change earphone
YES
Does it work well?
NO
Change the main board
- 70 -
NO
Check the soldering of CN300.8
Or change the earphone
Re-download software
Or check the soldering
NO
Voltage at
U301.5 and
U302.3 are high?
NO
YES
Voltage at
U300.1 is low?
YES
YES
Earphone will work properly
If not, check the U300, U301
NO
Copyright © 2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

NO