I think they all go wrong too soon. And as the cat hears whatever and not the human it's a often difficult to know if they're working at all.
I have 3 cat deterrents in my back garden, two are solar, one is mains (via power supply of course). The mains one has quickly gone to the stage of putting out a human audible tone every time I walk near so I conclude it's broken within months. The other two, I have little idea if they work. I don't get as much problem as I used to but that hasn't stopped some cat crapping next to one of them a few times.