4-2-3. SMPS / PANEL BACKLIGHT (Parallel Wired SMPS Panel Connections)
CNL801
LED Connector
CNL801 (LED Connector)
1
1+
2
1-
3
2+
4
2-
Backlight Test :
1. Activate Backlights Test
: Disconnect Lead Cable from Main to Power Supply.
9
Check TV Screen for active backlight LEDs.
2. If No Backlights
9
Minus (Control) pins & Plus (Supply) pins voltages on the Panel Connector. (
with fine test probe on left side of
connector only for safety
)
•
If no pin voltages replace
SMPS
.
3. If Backlights ON BUT PANEL SECTION(S) OFF
9
The Supply Drive (
+
) pins and (
-
) pins. All should measure same.
•
If a Minus (-) pin measures low (near 0 volts), a string(s) of LEDs are likely open.
9
Replace
Panel
.
•
If a (
+
) pin measures low voltage.
9
Defective
SMPS
BACKLIGHT DIMMING PROBLEMS :
•
Go to
Menu
£
Picture
£
Backlight
and vary level (0 – 50)
•
If no backlight changes observed:
9
Panel Connector
CNL801
minus (-) pin voltages
and
PWM_BLU
control voltages
CNM801
while changing
backlight level.
•
If
minus (-) pin voltages
don’t change, and
PWM_BLU
changes, replace
SMPS
.
•
If
PWM_BLU
doesn’t change replace
Main/T-Con Board
.
Backlight Test :
In normal TV operating mode, use standard
IR Remote
or
Factory Remote
with commands.
Go to
MUTE
£
4
£
1
£
9
£
EXIT
4-4
4. Troubleshooting
