Activate Backlights Test
1.
: Disconnect Lead Cable from Main to Power Supply.
TV Screen for active backlight LEDs.
9
If No BACKLIGHTS
2.
Minus (Control) pins & Plus (Supply) pins voltages on the Panel Connector. (
9
with fine test probe on left side of
connector only for safety
)
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.
•
Replace
•
Panel
.
If a
•
(
+
) pin measures low voltage and it’s minus pin is low but not 0V.
Check for Defective
•
SMPS
BACKLIGHT DIMMING PROBLEMS
Go to
•
Menu
£
Picture
£
Expert Settings
£
Backlight
and vary level (0 – 50)
If no backlight changes observed:
•
Panel Connector
9
minus (-) pin voltages
and
ANA-DIM
voltages
CNL801
while changing backlight level.
If
•
minus (-) pin voltages
don’t change, and
ANA-DIM
changes, replace
SMPS
.
If
•
ANA-DIM
doesn’t change replace
Main/T-Con Board
.
Use:
MUTE
£
4
£
1
£
9
£
EXIT
to test Panel Vertical Backlight Sections in normal operation mode.
4-12
4. Troubleshooting
