Thank you for the reply. It's not batteries, it's not the sensor, tried all that. Called Sharp tech support, was told a couple of reset options, tried all those, no help. Then Sharp tech person told me that she would give me the name of a repair shop in my area because they don't do repairs anymore and the location of a place I could buy a new remote because they don't replace them anymore. Not at all helpful, will never buy Sharp anything again. Will try option you suggested, because universal remote I tried worked the channels and volume but could not access Smart features, YouTube, Netflix, etc.
Any opinions on whether an Amazon Firestick or one of those Roku devices would help? Haven't used one before but thought since they are designed to reach those sites, it might work.