Yes, rusty. Well, oxidized connectors on the cable, but oxidation is just a fancy word for rust. I used to see this problem occasionally, maybe once every month or so, but over the past six months or so, I’ve seen dozens of examples of this problem causing iPhone charging problems. And before you ask, yes, the problem affects both third-party and genuine Apple cables. Is your cable affected? You can tell by looking at the gold fingers on the connector. If they look blackened or discolored, then you have a problem. Also: We’re facing a colossal Apple environmental timebomb You can clean the connectors, but in my experience, once this has happened the one time, it’ll keep on happening, and given the price of a replacement cable, I say go for that. My recommendation is to avoid USB-A charging cables. These connectors are prone to this problem whether the cable is fitted with a genuine Apple Lightning connector or a cheap third-party connector. There are a lot of good USB-C Lightning cable options out there. Here are a few that I have tried and tested and recommend: So what’s the solution? Replace the cable with a USB-C cable. These cables do not suffer from this problem. This is because they are designed to handle higher charging loads and built to higher standards. Note: Given the huge number of counterfeit Apple cables out there, if you want to replace your cable with a genuine Apple cable, then I highly recommend buying directly from Apple.
