LG KG70c Service Manual page 41

KG70C
3.3.4. When Rx Audio (Receiver, Speaker) isn't heard. 3.3.4. When Rx Audio (Receiver, Speaker) isn't heard.
Circuit Diagram Circuit Diagram
Pin #9 Pin #9
Pin #6 Pin #6
Checking Flow Checking Flow
wire soldering wire soldering
-Set RC3 & FCH -Set RC3 & FCH
Serv ice Option Serv ice Option
(Fwd3,Rvs3) , SO3 (Fwd3,Rvs3) , SO3
(Vo ice) in 5515C (Vo ice) in 5515C
-Set 1kHz Sine -Set 1kHz Sine
wave in Vo ice SO wave in Vo ice SO
Mode Mode
- Call connect. - Call connect.
U502 U502
START START
Receiver's Receiver's
OK? OK?
Yes Yes
Sine wave Appear Sine wave Appear
at the point of DNI_C530? at the point of DNI_C530?
Sine wave Appear Sine wave Appear
between pin#6 and #9 of U502 between pin#6 and #9 of U502
Resistance Resistance
Between 2 Between 2
Terminal of Terminal of
Receiver equal Receiver equal
To 8ohm? To 8ohm?
Change main board Change main board Change main board
C530(DNI) C530(DNI)
No No
Solder again the RCV Solder again the RCV Solder again the RCV
No No
Yes Yes
No No
Yes Yes
No No
Yes Yes
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Test Point Test Point
C30 C30 C30
U502 U502 U502
Figure 3-3-4 Figure 3-3-4
Change main board Change main board Change main board
Change the U502 Change the U502 Change the U502
Change Receiver Change Receiver Change Receiver