LG El
e
c
t
r
on
ic
s
/DND QA
LG El
e
c
t
r
on
ic
s
/DND QA
LG El
e
c
t
r
on
ic
s
/DND QA
LG El
e
c
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on
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/DND QA Gr
Gr
Gr
Gr
Non- image or same symptom when power off or black pattern.
1) Check CTRL B/D’s LED(D1~D4).
2) Check the power or signal cable input into CTRL B/D.
3) Check X B/D, Y B/D and Z B/D’s power connector.
4) Check the connector between CTRL B/D and X B/D, Y B/D, Z B/D respectively.
5) Measure each X, Y, Z B/D’s output waveform with over 200MHz oscilloscope and compare it to the below picture to detect the defect
and replace that.
- Y B/D measurement point : TP ( Connector P4 36 pin )
- Z B/D measurement point : panel connection part ( SUS_OUT )
- X B/D measurement point : L1(RIGHT), L2(LEFT BOTTOM)
< A: Y B/D output waveform - 1 FRAME >
< B: Y B/D output waveform - 1 SF >
1Frame(16.7ms)
Ⅳ
Ⅳ
Ⅳ
Ⅳ
.
.
.
. Non
Non
Non
Non-
-
-
-picture
picture
picture
picture Defect diagnosis.
Defect diagnosis.
Defect diagnosis.
Defect diagnosis.
5) Test scan(Y) IC.
6) Test data(X) COF IC.
7) Replace CTRL B/D.
< B: Y B/D output waveform - 2 SF(non-Setup SF) >
6)Test scan(Y) IC.
7)Test data(X) COF IC
8)Replace CTRL B/D.
