LG PDP42V5 Series, Service Manual

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2-8. The screen has one or several vertical
line
(1) In this case, It isn’t a problem about controller B/D or X
B/D.
(2) It may cause followings.
- It’s out of order a panel
- Open or short of DATA COF FPC attached panel
- It’s out of order a DATA COF attached panel
(3) Replace Module.
[ [
Screen Display Form
2- 9. The screen has one or several
horizontal line
(1) In this case, it isn’t a problem about controller B/D or X
B/D.
(2) It may cause followings.
- It’s out of order a panel
- Open or short of SCAN FPC attached panel
- It’s out of order a SCAN IC attached panel
(3) Replace Y DRV B/D
[ [
Screen Display Form
2-10. The screen displays input signal
pattern but the brightness is dark
(1) In this case, Z B/D operation isn’t complete.
(2) Check the power cord of Z B/D.
(3) Check the connector of Z B/D and Controller B/D.
(4) Replace the Controller B/D or Z B/D.
2-11. The screen displays other color
partially on full white screen or happens
discharge partially on full black screen.
(1) Check the declination of Y B/D set up, set down wave.
(2) Check the declination of Z B/D
˙
ramp wave.
(3) Measure each output wave with oscilloscope(more than
200MHz) and compare the data with below figure data.
Adjust the Y B/D set up(Test-up:B/C[
¥
s/
¥
s])/setdown(Test-
down:D[
¥
s]) and Z B/D ramp(Tramp:F/G[
¥
s/
¥
s]) declination
by changing VR1/VR2/VR3.
- Measuring Point of Y B/D : P4 (Connector P4 36 pin)
- Measuring Point of Z B/D : B37 (SUS_OUT)
2-12. A center of screen is darker than
a edge of screen at full white pattern.
(1) In this case, it’s a problem about Z B/D ramp wave.
(2) Check the connection cable of Z B/D and CTRL B/D.
(3) Replace the Z B/D.
[ [
Screen Display Form
2-13. It doesn’t display a specified
brightness at specified color
(1) Check the connector of CTRL B/D input signal.
(2) Replace the CTRL B/D.
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It may show several vertical
lines in a quarter or other
division part of screen
including left case.
It may show several horizontal
lines including left case.
Y Output Voltage Wavefrom Z RAMP Voltage Wavefrom