Samsung UN40K6500AG Service Manual page 38

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