Hitachi P50H401/DW3-U Service Manual page 128

TROUBLESHOOTING THE PANEL
4.5 Fault Symptom
Fault contents
No
1
Entire screen does not
light (No Picture)
2
3
Vertical Line
4
5
Vertical Bar
6
7
Horizontal Line
8
9
Horizontal Bar
10
11 Image sticking
(or Image retentions)
Twinkle
12
13 Flicker
Luminance is abnormal
14
15 Crominance is abnormal
16 Sync is disturbed
Picture is Distorted
17
Some steps of gradation
18
are skipped
19
Abnormal Noise
Control of external
20 communication is
abnormal.
Fault status
After momentarily lighting, the
screen becomes black
immediately or after a few
seconds.
(Main power is turned off.)
Screen does not show any
picture but lights dimly.
Single vertical line
Vertical line from middle of
Screen. Vertical line of
Different Color
Vertical bar with 1/15 or its
multiplication width of screen.
Vertical bar with 1/2 width of
screen
Single Horizontal line (Does not
light) or Single Horizontal line
does not light in entire screen
Every other lines do not light in
entire screen
Bar width of 1/8 of vertical size of
the screen does not light
Bar width of 1/2 vertical size of
the screen does not light.
Could be Top or Bottom.
Fixed contents are always visible Fixed contents are always visible
The entire screen momentarily becomes
brighter or darker.
The entire screen flickers continuously
Luminance can not be displayed correctly
Colors can not be displayed correctly
Syncronization is abnormal
There is an image, but it is not normal.
Luminance linearity is poor.
Unusual Noise coming from inside the set.
Some Panel Noise is Normal
unable to adjust Contrast, Chrominance
and gamma value.
P50H401
Suspected fault
See Troubleshooting
Pg. 58 & 127.
LOGIC
LOGIC
PANEL
ABUS-A/B/C
LOGIC
And related connection
PANEL
ABUS-A/B/C
LOGIC
And related connection
Make sure connector
from SDR to Panel is
correctly seated.
1/2 Line = Panel
X-SUS
Y-SUS
SDRU and D
Make sure connector from
SDR to Panel
is correctly seated.
If connection ok.
SDR-U or D
SDRU or SDRD
May be Top
Y or X-SUS
And related connections.
May be Bottom
In some cases, residual
images may remain after
Text or Graphics
the short term display of
of any kind. still images when the
picture changes. NORMAL
Loose contact on
Connector
Loose contact on
Connector
LOGIC
LOGIC
LOGIC
LOGIC
LOGIC
POWER SUPPLY,
X or Y-SUS, Cabinet
LOGIC
126
Analysis procedure
location and measure
Replace defective PCB
See "No Picture"
Troubleshooting Flowchart
Pg. 58
Replace
LOGIC board
See Vertical Line
Troubleshooting Flowchart
Replace Panel
See Vertical Line
Troubleshooting Flowchart
See Vertical Bar
Troubleshooting Flowchart
Full line, check SDR
connector to Panel.
Any line short of full
Exchange Panel
Exchange X-SUS or Y-SUS
Exchange SDR-U or SDR-D
Exchange SDR board
See Horizontal Bar
Troubleshooting Flowchart
Lower Contrast & Brightness
Set Image Power to MID
Perform Screen Wipe
Re-Connect cables
or replace defective cables
on LVDS connector on
Logic PWB
Exchange LOGIC
Exchange LOGIC
Exchange LOGIC
Exchange LOGIC
Exchange LOGIC
Find defective part by
watching and hearing, after
replace defective part.
Exchange LOGIC PWB