BACKLIGHTS
Activate Backlights Test
1.
:
Disconnect Lead Cable from Main Board to Power Supply.
-
TV Screen for active backlight LEDs.
√
If NO BACKLIGHTS
2.
Minus (Control) & Plus pins (Supply) on the Panel Connector voltages to the Panel.
√
If no pin voltages replace SMPS.
-
If BACKLIGHTS ON BUT PANEL SECTION(S) OFF
3.
The Supply Drive
√
+
pins. All should measure same.
If a
-
+
pin measures higher voltage, a string(s) of LEDs are likely open.
Remove Panel connector and verify same open backlight voltage condition.
-
Replace Panel
.
If a
4.
+
pin measures low voltage disconnect connector to panel
The Low Plus Pin Voltage again.
√
If it stays low the
-
SMPS
is defective, if it goes high, defective
Panel
.
For BACKLIGHT DIMMING PROBLEMS:
Go to
•
Menu
£
Picture
£
Backlight
and vary level (0 – 20)
If no backlight changes observed:
•
Panel Connector minus (-) pin voltages and P-DIM voltages (CNL801) while changing backlight level.
√
If minus Panel voltages don’t change, and P-DIM changes, replace
•
SMPS
.
If P-DIM doesn’t change replace
•
Main/T-CON Board
.
MUTE
4
1
9
EXIT
to test Panel Backlight Sections.
4-6
4. Troubleshooting
