Panasonic Viera TXP50XT50B won’t turn on

Hello i’ve got a Panasonic VIERA 3D tv and it won’t come on after my electric went out,no lights or nothing the model number is TXP50XT50B, this happens when I unplug it or trip switch goes or electric, normally I just leave power cable out put it back in occasionally and it will start working again. It’s took anywhere from a few minutes up to a month for me to get it back on before, thanks.