So I just sold my iPhone 7 to someone on eBay. Well I say just, it was about 2 weeks ago. Today they told me that they just tried out my iPhone and the sound won't work over the headphones. Said everything else is fine, charges and everything, just won't play sound over the headphones. Now I listened to sound from the headphones pretty much every day of the 2 years I had the phone, so I told him to try to adjust the volume and asked if it was recognizing that headphones were even attached. He got defensive and said he was taking it to the Apple store. I realize I could be getting scammed because, well, eBay. But is there something else I could suggest the guy do? He tried it on 2 pairs of headphones (I had shipped it with the set that came with my iPhone XS since I didn't think he'd want headphones that had been in someone's ears.) The phone had literally no issues before it went to him. I babied that thing.