No change in behavior, even with the jumper, disconnecting one or both U-loops still causes power cycle...

Yeah, it's definitely a panel issue.
I still wonder If I can get any image to show up, even if it's bad....

Got this 75" TV for free, spent 10+ hours looking into solutions and troubleshooting methods before posting, I would hate for this device to become e-waste.

[B]The issue:[/B]
backlight turns on, goes dim, turns off and the red light blinks twice.
unlike the numerous videos I have seen online I can hear an audible click from the relay switch on the p9wer supply board.

[B]What I tried[/B][B]:[/B]
disconnecting the main board from the power supply = backlight turns on and stays on.
disconnecting the ribbon cable from the mainboard = backlight...

Hello ya'll, I'm David I hate throwing electronics away and I'd rather repair and fix if possible!

Cheers