BACKLIGHTS
Activate Backlights Test1. :
Disconnect Lead Cable from Main Board to Power Supply. (CNM803) -
TV Screen for active backlight LEDs. √
If NO BACKLIGHTS2.
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) OFF3.
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 pin voltages and BLU_PWM voltages (CNL802) 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.
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