Lg Electronics LGC800W User Manual
LGC-800W
LG Information & Communications, Ltd.
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5. When Keytone isn't heard.
START
Good
Keytone heard
at handset?
Yes
No
Supply Power
to Handset
Check signal
at R976?
Change Earpiece
Change
Main Board
No
Yes
Rectangular
wave appear 5/8 pin
of U971
No
Yes
Voltage
of U802
= 3.3V ?
Change U802
No
Yes
Change U971
Yes
Rectangular
wave appear 4 pin
of U971
Check Ext. Ring
Ambient circuit
No
6. When Buzzer isn't rung.
START
Paging to Handset
with HP8924C
Service option 1.
Change Q803
Yes
Change Main Board
No
Check Q803
V_H at Base
Rect. wave
at Emitter
Yes
No
3.6V
at Collector
Yes
No
Change Q801