Samsung UN J5500AF Series Service Manual page 107

UN40J5500AFXZA Fast Track Troubleshooting Manual Rev 6/15/15cr
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
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.
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.
("TV Power On" Problem)
.2Vdc (when off) to 3.3Vdc (turned on)
(.2V eff. dc at min. bright to 3.3V eff. dc
("TV Power On" or
"No Backlight" Problem)
CN201 Main BD Side
CNM803 SMPS to Main
2 A13V 1
4 GND 3
6 PS_ON 5
8 SW_INVERT 7
10 OVD_LEVEL 9
12 ANA_DIM 11
Jog Function Test ("TV Power On" Problem)
1. In STBY Check LED Ind. for 1.7Vdc and
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
If the voltage is low and remains low the
CNL802
CNL802 (to BLU)
15 IF2
13 NC
11 1 -
A13V
9 NC
GND
7 2-
A13V
5 NC
A13V
3 3 -
A13V
1 NC
FET_FAIL
DETECT
VCC for 3.3Vdc. If missing check the
("TV Backlight" Problem)
SMPS is defective.
16 IF1
14 NC
12 NC
10 1+
8 NC
6 2+
4 NC
2 3+
Panel.