Three nights ago, our power flickered off and then right back on during the night which made the TV go off. I tried turning the TV back on and the little green power light keeps flashing and will not go off. I have unplugged it several times, waited for 25 minutes to as long as 8 hours, but once I plug it back in, the little green power light will not stop blinking. My power button will not turn the tv on until the green light stops blinking. What could be the cause of this? How much does this type of repair cost?