LG KF750 Service Manual page 124

4.11.5 Headset MIC(Voice call, Video Telephony)
START
Insert Headset.
Does the Headset icon display
on the main LCD?
4
Check the signal level
at U803 at the putting
Audio signal in MIC
A few hundred of mV
of the signal
5
at U803 ?
Change the main Bíd
Does it work properly ??
END
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
NO
YES
6
NO
measured
YES
NO
YES
- 125 -
1
Does the level of R621
under 0.5Volt ?
YES
YES
Change the main B,d
3
Resolder U803
and try again.
If fail again,
Change the main Bíd
Try again from the start
NO
2
Does the level of R621
over 1.6Volt ?
N0
Resolder R620
And try again from the start
LGE Internal Use Only