My screen is black, no sound. Menu won't come up, or input button. Green power light is on though.

if the power light comes on but the screen stays black, then your TV might be on the wrong input Channel. for example: you switch inputs when you play games or watch dvds vs. watching regular tv. Try to change the input

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/laura_08254539050d64db

Sounds like the main board causing that type of symptom. You can get replacement main boards from www.tvrepairworld.com

Replace the medieval TV.

It will need to be checked and boards replaced to know which if any are causing this trouble--I presume it happens on all inputs including the rear ones.

Try changing the input device to something you are sure works. Switch off TV manually, switch off power, remove plug and retry after 48 hours. If problem persists, please refer it to a qualified service technician.

The flashing green light is likely indicative of a self-test failure, indicating the TV has detected some sort of internal fault. With no picture or sound, one strong suspect is the power supply. Flat-panel TV's have an internal DC power supply that converts the inbound AC current, and when these fail, or are unable to supply a minimum level of power to the set, it can behave as you describe, providing only enough power for the green light to illuminate.

My monitor has been switching connections on me randomly. Hit the menu button. The one to the left of the power butter when facing the screen. Hit the left arrow twice then hit the menu button again. This will open up the screen where you can choose one of three inputs. I'm going to assume that it is on the incorrect input so use the arrow keys highlight what input you are using and the hit menu button again and your screen should return to normal. Mine only does this randomly when it goes into screen saver, hibernate or sleep. I don't know how to permanently get it to stop doing it though.

you may be on the incorrect input channel. look for an input or tv video button and choose each input until u get a picture

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/laura_08254539050d64db

press the input button until it cycles through all of the inputs.