LG 42LF75 / 42LF76 (CHASSIS:LD75B) Service Manual ▷ View online
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(4) In the case of becomes unusual display from side S-video/AV mode
Is Video input of the
AV Jack (P1400)
normal?
Check the input source.
Is normal the Input voltage,
IICCommunication and HV sync?
Yes
No
No
Replace IC
No
Replace IC
No
Is normal the
CXA2069Q?
Yes
Same as Block A
(5) In the case of becomes unusual display from Component, RGB mode
Is R,G,B input and
H,V Sync of the J1100
normal?
Yes
Check the input source.
No
Same as Block A
(6) In the case of becomes unusual display from HDMI mode
Is normal the
HDMI002 (IC1004)?
Yes
Is normal the Input voltage, IIC
Communication and HV sync?
No
Same as Block A
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(7) In the case of becomes unusual display from SCART1 mode
Is Video input
of A/V jack normal?
(J1200)
Yes
Check the input source.
No
Same as Block A
(8) In the case of becomes unusual display from SCART2 mode
Is Video input
of A/V jack normal?
(J1201)
Yes
Check the input source.
No
Same as Block A
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5. In case of no sound
(1) Symptom
1) LED is green.
2) Screen display but sound is not output
2) Screen display but sound is not output
(2) Check follow
All input (mode)
is no sound?
Is the speaker
On it men?
Set on speaker in
menu.
Is the speaker
Cable normal?
Check the Speaker
Cable
IC1300 operates
Normal?
Replace IC1300
(MSP4450)
IC1301 operates
Normal?
Replace IC1301
(STA335BW)
Replace VSC BD
Yes
No
Only HDMI is
No sound?
Yes
Download
the EDID data.
No
No
No
No
No
Only RF is
no sound?
no sound?
Yes
Check
the Tuner IN/OUT
No
Check the signal before
CXA2069 refer to circuit diagram
Only
AV/component/PC
input is no sound?
Yes
Only specific input
(except HDMI,
DTV,RF) is no
DTV,RF) is no
sound?
Yes
Is the output of
CXA2069 normal?
Check the signal after CXA2069
refer to circuit diagram
No
Replace CXA2069
No
Yes
Yes
Yes
Yes
No
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BLOCK DIAGRAM
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