I've only had this tv for a month, the remote is transmitting, I've tested it, the sensor on the tv seems like it's not working. If I unplug the tv for awhile it will work for a short time then the red led light will flicker and go out. Now unplugging it is not helpful. It's a Hisense Roku tv Model 32H4030F1 any ideas? The store wouldn't replace it.