LG MG180C Service Manual page 67

4. TROUBLE SHOOTING
1. Earpho ne detecti on problem
The Volt age
at HOOK_DETECT point
is 0V?
Yes
2. Send ing Pat h problem
The vo ltage at L200
is 0. 99V ~ 1.03V?
tens or h undreds
of mV of signa ls at C221
are measur ed ?
The ABB is out of order.
Change th e board.
No
Set audio part of the test
equipment to the echo mode.
No
Yes
A fe w
No
Yes
Soldering
Of C208, R207 is OK?
Yes
Pin3 an d Pin4 of J 200
are ope n?
Yes
The ABB is out of order.
Change th e board.
Re_sold er the
R202, R205
The
solder ing of C 221
is O K?
Yes
The
solder ing of J 200
is O K?
Yes
The earphone is O K?
Yes
The ABB is out of order.
Change th e board.
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No
Re_sold er the
C208, R207
No
Change th e J200
No
No
No