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4. Troubleshooting
„ Backlight Test :
1. Activate Backlights Test : Disconnect Lead Cable from Main to Power Supply.
Check TV Screen for active backlight LEDs.
9
2. If No Backlights
Check BL Supplies (CH1, CH2) on SMPS (approx. 270Vdc for 65")
9
Also Check CH3, CH4 included for TVs 75" & larger
9
→
If missing replace SMPS Board.
3. If BACKLIGHTS ON BUT PANEL SECTION(S) OFF
Locate CH1 + on SMPS and measure for approx. 270Vdc (65")
9
Locate CH1 (– ) on SMPS and measure for approx. 100Vdc (65")
9
→
If CH1 (+) is very low or missing replace SMPS Board
→
If CH1 (+) is OK & CH1 (-) is near 0 Volts replace Panel
Locate CH2 (+) on SMPS and measure approx. 270Vdc (65")
9
Locate CH2 (– ) on SMPS and measure for approx. 100Vdc (65")
9
→
If CH2 (+) is very low or missing replace SMPS Board
→
If CH2 (+) is OK & CH2 (-) is near 0 Volts replace Panel
Also do same Check CH3, CH4 on SMPS for TVs 75" & larger
9
BACKLIGHT DIMMING PROBLEMS:
1. Go to
Menu
Picture
£
2. If no backlight changes are observed vary the level again:
Check
PWM1
/
PWM2
9
→
If it doesn't vary voltage replace Main/T-CON Board.
→
If it changes replace SMPS.
•
New
is
PWM1 Blue
&
Backlight error would appear)
4-18
CNL801
1
1+
2
2+
3
2-
4
1-
5
3+
6
4+
7
4-
8
3-
9
N.C
10
N.C
11
N.C
12
N.C
Backlight
and vary level (0 – 50)
£
control voltages CNM801 varies approx. 0.5V – 2.5Vdc
PWM2 White
that changes with backlight level (if Blue is 0V - "Yellow" if "white" 0V "Blue"
1
Vf CH1
2
CH1 /
3
PWM1
4
PWM2 (White_high)
5
Vf CH2
6
PWM1 (Blue_low)
7
CH2 /
8
PWM2
9
10
11
12
CNM801
GND
ANA-DIM
A13V
A13V
A13V
Power On/off
A13V
GND
GND
GND
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