Advent televison remote not working?

My aunt has a television made by Advent. a week or so ago her remote control stopped working (the controls on the front of the tv work fine) (batteries in the remote are fine) . She went out and purchased a universal remote and I tried to set it up for her. I'm pretty good with setting things like that up, but the universal remote will not work with her tv either apparently. How likely is it that sensor on the tv itself or something else in the tv went bad instead of the actual remote?