Samsung UN TU7000F Series - Page 41

 Backlight 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 NO BACKLIGHTS
9 Check CH1 (+) BL Supplies on SMPS (approx. 270Vdc for 65”)
9 Also Check CH2(+), CH3(+), CH4 (+)..etc. when included for larger TVs
→ If any missing replace SMPS Board.
→ If supplies are OK replace Panel.
3. If BACKLIGHTS ON BUT PANEL SECTION(S) OFF
→ Repeat Step 2.
→ If any CH Backlight Supplies are low or missing replace SMPS.
→ If supplies are OK, replace panel.
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.
4-7
4. Troubleshooting