2014-04-29, 12:15 AM
I had something similar happen on a Vizio TV. After reconnecting the cable, it would power on but only black screen. I unplugged the power cord hoping it would reset but no luck. I finally disconnected all the cables to haul it off, but on a whim, plugged it back in one last time. It worked perfectly normal. My suspicion is that the non-power cables (speakers etc) keep the TV grounded to the electric system even when the main power cord is unhooked. If there are capacitors inside, they could supply the 'positive' power and keep the TV's internal computer from rebooting until everything is totally disconnected. That TV is still working many years later 