Chargers look fine but aren’t working

I have two iPhone chargers that don’t work. I’ve checked for corrosion/ripped cable/plug issues/outlet/iPhone itself, these chargers just don’t work. I don’t know what to do because nothing seems to work. Both chargers stopped working after a few months of use as well. They aren’t official iPhone chargers, but my family has the exact chargers and they still work. At the moment I’m using a charger held together by athletic tape because these other chargers just don’t seem to work. if anyone has had a similar issue please let me know how it’s fixed.