BACKLIGHTS
Activate Backlights Test
1.
:
Disconnect Lead Cable from Main Board to Power Supply. (CN202)
-
TV Screen for active backlight LEDs.
√
If NO BACKLIGHTS
2.
Plus (+) & Minus (-) pin voltages on the Panel Connector.
√
If no pin voltages replace
-
SMPS
.
If voltages exist but no backlight:
-
The highest pin voltage (
√
BL Drive Supply
)
Remove Panel connector
-
and measure again to compare.
If the voltage was high
-
and stays the same high reading a string of Panel LEDs are open. Replace the
Panel
.
If the v
-
oltage was low
and remains low the
SMPS
is defective.
If the voltage was low and goes high a string of panel LEDs are shorted replace the
-
Panel
.
For BACKLIGHT DIMMING PROBLEMS:
Go to
•
Menu
→
Picture
→
Backlight
and vary level (0 – 20)
If no backlight changes observed:
•
Panel Connector pin voltages and BLU_PWM voltages (CNM801) while changing backlight level.
√
If Panel voltages don’t change, and BLU_PWM changes, replace
•
SMPS
.
If BLU_PWM doesn’t change replace
•
Main/T-Con Board
.
4-4
4. Troubleshooting
