SMPS / PANEL BACKLIGHT (Parallel Wired SMPS Panel Connections)
Activate Backlights Test
1.
Disconnect Lead Cable from Main Board to Power Supply.
-
55" :
CN9003
65" :
CMN803
TV Screen for active backlight LEDs.
9
If NO BACKLIGHTS
2.
Minus (Control) pins & Plus (Supply) pins voltages on the Panel Connector.
9
If no pin voltages replace SMPS.
•
If BACKLIGHTS ON BUT PANEL SECTION(S) OFF
3.
The Supply Drive
9
+
pins and - pins.
All should measure same
.
If a
•
Minus (-) pin measures low (near 0 volts), a string(s) of LEDs are likely open.
Can remove Panel connector and verify same open backlight voltage condition. Replace
•
Panel
.
If a
•
+
Pin measures low voltage disconnect connector to panel.
The
9
+
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 (
9
CN9003
) 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
