Backlight Test: (Extended Test)
CNL801
(LED Connector)
65"
1 1+
2 1-
3 2+
4 2-
5 3+
6 3-
7 4+
8 4-
9 5+
10 N.C
11 N.C
12 5-
VF CH1
Dim.
CH1
CNL801
(LED Connector)
58"
1 1+
2 1-
3 2+
4 2-
VF CH1
Dim.
CH1
CNL801
(LED Connector)
70" / 75"
1 1+
2 1-
3 2+
4 2-
5 3+
6 3-
7 4+
8 4-
9 5+
10 5-
11 6+
12 6-
VF CH1
VF CH2
Dim.
CH1
Dim.
CH2
CH1(+)
250Vdc
CH1(-)
60Vdc
[65” TV Example]
Panel BL Connector: Sets of LED BL Strings example (connected in series - if one fails all go off)
1. Activate Backlights Test : Disconnect Lead Cable from Main to Power Supply.
9 Check TV Screen for active backlight LEDs.
2. If BACKLIGHTS OFF or PANEL SECTION(S) OFF
9 Locate CH1 (+) on SMPS and measure for approx. 250Vdc (65”)
9 Locate CH1 (– ) on SMPS and measure for approx. 60Vdc (65”)
→ If CH1 (+) is very low or missing replace SMPS Board
→ If CH1 (+) is OK & CH1 (-) is near 0 Volts replace Panel
3. Larger Size TVs :
9 Check CH2 (+) and CH2 (-) when included for Larger TVs
→ Repeat the same Test as with CH1
9 Continue to Check CH3, CH4, …, etc. when they are also included.
BACKLIGHT DIMMING PROBLEMS:
9 First check Option Byte Settings in Factory Mode. Wrong settings can create backlight errors.
1. Go to
Menu
£
Picture
£
Expert Settings
£
Backlight
and vary level (0 – 50)
2. If no backlight changes are observed, vary the level again:
9 Check
BLU_PWM
(pins
6
) control voltages
CNM801
varies approx. 0.5V – 2.5Vdc
→ If it doesn’t vary voltage replace Main/T-CON Board.
→ If it varies and back lights won’t dim, replace SMPS.
4-8
4. Troubleshooting
To Next Page
Loading...
