Yeah try a reset first, press and hold the home button and the power button at the same time until the phone shows the apple logo then release. See if that works, failing that, get some like a cocktail stick or a needle and carefully try to see if theres any dust/fluff in there, i had loads in both my headphone port and the charging ports, neither had a problem but i was just cleaning the phone and thought id have a poke in there to see what came out, and i was amazed at the amount of crud in there! and it was an Iphone 6S, so not really that old either.
