Power- Up Sequence / Test
1. Check Standby: A13V (Always On) to Main Board. Measures
between 7.5VDC & 12.7VDC (if missing Check AC Line fuse/replace
SMPS).
2. Turn TV Power on: PS_ON .2Vdc (when off) to 3.3Vdc (turned on)
if missing replace Main Board.
3. The A13V is then raised to full voltage level 12.7VDC.
4. BLU_PWM (PWM_BLU): .9V~3.3Vdc . Backlight On/Off & Backlight
PWM signal Level Control.
(.2V eff. dc at min. bright to 3.3V eff. dc
at max. bright)
Forced Backlight/SMPS-On Mode:
1. Disconnect Power Cord
2. Disconnect wire harness from CNM803
3. Re-Connect Power Cord
4. SMPS & LED Backlights should immediately turn on.
CN201 Main BD Side
Jog Function Test
1. In STBY Check LED Ind. for 1.7Vdc and VCC for 3.3Vdc. If missing check the
STBY voltage from SMPS to Main Board. If STBY is OK suspect Main Board.
2. Check Jog Shuttle 5 SW Operation (Key 1 & Key 2) for command changes. If
incorrect suspect a stuck Jog switch which also holds data to Main preventing
operation.
3. Check SDA, SCL for effective 3.3Vdc (after power on)
4. Check IR with Standard Remote command changes. (3.3V to 2,5V effective DC)
Backlight Test: LED Panel Series Connection
1. Place TV in “Forced Backlight On Mode”
2. Check Screen for active backlight LEDs.
3. If no backlights, check minus & plus pins on the Panel Connector for drive
voltages to the Panel.
4. If no pin voltages replace SMPS.
5. The highest pin voltage is BL Drive Supply from SMPS.
Remove Panel connector and measure again to compare. If voltage is high and
stays the same high reading a string of Panel LEDs are open. Replace the Panel.
If the voltage is low and remains low the SMPS is defective.
(“TV Power On” Problem) (“TV Power On” Problem)
(“TV Power On” or
“No Backlight” Problem)
(“TV Backlight” Problem)
CNL802 (to BLU)
15 IF2 16 IF1
13 NC 14 NC
11 1 - 12 NC
9 NC 10 1+
7 2- 8 NC
5 NC 6 2+
3 3 - 4 NC
1 NC 2 3+
CNM803 SMPS to Main
2 A13V 1 A13V
4 GND 3 GND
6 PS_ON 5 A13V
8 SW_INVERT 7 A13V
10
OVD_LEVEL 9 A13V
12
ANA_DIM 11
FET_FAIL
DETECT
CNL802
UN40J5500AFXZA Fast Track Troubleshooting Manual Rev 6/15/15cr
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