Samsung QN55Q75CNF Service Manual page 45

4. Troubleshooting
1. Power TV On
A13V pin 17 (Supplied by One Connect Box)
9
• If missing check One Connect Operation & Cables to the TV
PS_ON pin 19 .2Vdc (when off) changes to 3.3Vdc (on)
9
NOTE
• Will stay On for short time when powered off.
2. If PS_ON Error (won't change or missing voltages)
Check & perform "Function Control Test" Operation
9
3. If PS_ON is OK
B350 (from OCB) for approx 346Vdc at pins 5 & 6 while using important B-GND reference at pins 1 & 2
9
• If missing check One Connect Operation & Cables to the TV
("PS ON" activates B350V Supply in One Connect Box)
4. If B350 & A13V are OK
B13V Switched Supplies for 12.8Vdc at pins 12,14,16
9
Vamp (Audio amp supplies) for 18Vdc at pins 11,13,15
9
5. If no B13V or Vamp voltages
Resistance on SMPS
9
• If fuse is open Replace SMPS
6. If wrong B13V or Vamp Voltages:
Replace SMPS
9
TV Main Board (If defective can load down SMPS)
9
7. Backlight ON
BLU_ON 0V (when Off) to 5Vdc (on) at pin 26
9
• If no change replace TV Main Board or OC Box
NOTE
The Panel SMPS can be disconnected completely and the Panel will still have Standby Light and attempt Power On.
This is because the 13A Vdc supply is from the OCB and connects directly to the TV Main Board.
4-4
FUSE after first removing CNM803