LG 50PT81-ZB (CHASSIS:PP7BA) Service Manual ▷ View online
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9. In the case of an unusual display in SCART 1 mode(main).
Is the video
input of the A/V jack
normal?(Check R102)
Yes
Sam as Block A
Check the input source.
No
10. In the case of an unusual display in SCART 1_RGB mode(main).
Is the
video input of
the A/V jack normal?(Check
L111, L112,
L112)
Yes
Sam as Block A
Check the input source.
No
11. In the case of an unusual display in SCART 2 mode(main).
Is the video input of
the A/V jack normal?
(Check R115)
Yes
Sam as Block A
Check the input source.
No
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12. In the case of an unusual display in SCART 2_YC mode(main).
Is the video
input of the A/V jack
normal?(Check
R115,R149)
Yes
Sam as Block A
Check the input source.
No
13. In the case an unusual display in RF mode(Sub).
14. In the case PIP doesn’t display in other mode(Sub).
- Same as the case of main except block A should be change to B
Check the power.(L1004)
Is the
video output of the
CXA2069Q normal? (Check R312,
in case of S-Video
Check R312,
R314)
Is the
input voltage
normal?(Check
L308)
Yes
No
Yes
Is the LVDS
Cable connected?
Yes
Change the IC(IC700)
Re-insert the cable.
No
Change the IC(IC300).
No
B
Check the power.
Is the
video output of the
Tuner normal? (Check
TU201_Pin14)
Is the
input voltage
normal?(Check Pin8,
Pin6)
Is the I2C communication
normal?
(Check Pin5, Pin4)
normal?
(Check Pin5, Pin4)
Yes
No
Yes
No
Check the Tuner.
No
Re-insert the cable.
Is the
Tuner Cable
connected?
No
No
Is the
I2C communication
normal? (Check
R309, R310)
No
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15. In the case of an unusual display in component 1 mode(main/sub).
Is the video
input of the JK102
normal? (Check L126,
L127,L128)
Yes
Change the IC(IC700)
Check the input source.
No
16. In the case of an unusual display in component 2 mode(main/sub).
Yes
Change the IC(IC700)
Check the input source.
No
Is the video
input of the Jk103 normal?
(Check L129, L130,
L131)
17. In the case of an unusual display in RGB mode(main/sub).
Yes
Change the IC(IC700)
Check the input source.
No
Is the
R, G, B input
and H, V sync of the
JK500 normal?(Check R509,
R511, R512, R513,
R515)
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18. No Sound
(1) Symptom
1) LED is green.
2) There is a picture but no sound.
2) There is a picture but no sound.
(2) Follow check
Is there sound in any
mode?
Is the speaker
on?
Yes
Yes
Is the speaker
cable normal?
cable normal?
Yes
Yes
Is there no sound
only for HDMI?
Yes
Is there no
sound only AV?
Is the output
of IC300(Pin52,53)
normal?
Yes
Is there no sound
only for RF?
No
No
No
No
Download the EDID data.
Set speaker on
in the menu.
in the menu.
No
Replace the
IC300
No
Check the Speaker
cable
cable
No
Is the IC400
operating normal?
Replace the IC400
No
Yes
Is the IC401
operating normal?
Replace the IC401
Replace the VSC B/D
Yes
Check the signal after IC300.
refer to circuit diagram.
refer to circuit diagram.
Check the Tuner In/Out.
No
Yes
Is the IC402
operating normal?
Replace the IC402
No
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