DIAGNOSIS The panel isn't getting power, likely due to the One Connect Box cable not being fully seated. It's a super common setup snag with this model.
FIX
First, power everything down and unplug the TV from the wall.
- Go to the One Connect Box (the small black box with all the ports).
- Firmly disconnect the single, thin, flat cable that runs from it to the TV panel.
- Visually check the connectors on both ends for any bent pins or debris.
- Reconnect it with a decisive, solid click. You should feel it latch.
- Plug the TV back in and power it on.
IF THAT DIDN'T WORK Try a different power outlet for the One Connect Box and ensure its power cable is also secure. If the panel is still dark, the One Connect cable itself might be faulty and needs replacement from Samsung.
HEADS UP Never twist or force the One Connect cable. It's designed to connect straight in and out. Bending it can damage the internal wires and cause intermittent black screens.