You can take a small flat head screwdriver and prise the sensor gently out of the casing while the tv is unplugged. Clean inside the casing, connectors etc, and also on the ir sensor itself with some pure alcohol and lint free cloth. Place back in casing until it clicks then switch on TVs and see if it works. If all else fails, buy a new sensor for your model tv and replace. These are cheap as chips.
MeMyselfAndI
January 2016