Thanks for the reply.
Unfortunately I do not have good news for you. There is no sequence of buttons you can press the reset the TV, and it will require circuit testing and component replacement to operate properly again.
There are basically three problems that would cause this, the Power Supply, the Backlight Inverter boards, or the LCD panel itself has failed. Voltages need to be measured at the power supply outputs, using a DMM with nothing connected to it but AC Input. If the readings are proper, then the other boards need to be connected one at a time, until one causes the voltage to shut down at the output. If the supply outputs power with all of the boards connected, then the backlight inverters need to be tested. The backlight inverters will run you around $450 to have replaced. If the LCD panel is receiving power from the inverter boards, then it has failed and will cost you more than a new TV (around $1100) to have replaced and it is not cost effective to repair this set.
If you do not have experience testing live voltages on a circuit board level, then I would suggest using the link below to locate a tech in your area:
If you need further assistance, let me know.
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