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
t
r
on
ic
s
/DND QA Gr
Gr
Gr
Gr
10. Input signal pattern is displayed but the whole brightness of the screen is dark.
1) It happens when Z B/D is not operating well.
2) Check whether Z B/D’s power connector is plugged .
3) Check whether the connector between Controller B/D & Z B/D is plugged.
4) Replace Controller B/D or Z B/D.
11. In full white pattern, foreign color is displayed or in full black pattern, mis-discharge
is partially occurred.
1) Check the slope of Y B/D set up, set down waveform.
2) Check the slope of Z B/D’s ramp waveform
3) Measure each B/D’s output waveform by over 200MHz oscilloscope and compare it to the below picture.
it is possible to control Y B/D’s setup slope by adjustinng VR2, setdown slope by VR1 and Z B/D’s ramp slope by VR1
..
- Y B/D measurement point : TP ( Connector P4 36 pin )
- Z B/D measurement point : panel connection part ( SUS_OUT )
setup
setdown
230
µ
s
25
µ
s
230V
Vsetup
175V
Vs
Y output voltage wave
175V
Vs
15
µ
s
20
µ
s
Z RAMP voltage wave
0V
