Turning the Eco Sensor off disables the automatic ambient light brightness adjustment, which can be a source of flickering. You could also disable the Energy Saving feature. Energy Saving off to prevent your TV from automatically adjusting brightness based on the show you are watching. This may solve your flickering problem. Test your TV on a different power source if you can. If it's still flickering, the issue could be caused by a faulty cable, bad connection or malfunctioning TV component.
It will not turn on for me to turn off the energy saver. It just flickers and no red standby light at all. I have moved it to a separate power source and no change. I have a feeling it is a lost cause.