iPhone 12 Pro only charges with USB C to iphone

It seems like you might be referring to an issue where a USB A to Lightning cable isn't effectively charging an iPhone 12 Pro. The primary factor to consider in this scenario is the type of adapter being used in conjunction with the USB A cable. If you're experiencing this problem, it's important to recognize that the type of cable being utilized can significantly impact the charging process.

If you find that a USB C to Lightning cable successfully charges the iPhone 12 Pro, this outcome indicates that the iPhone itself is not the source of the problem. Instead, it points to the USB A cable or the adapter as potential culprits.

USB A cables are known for being compatible with a wide range of devices; however, their charging speed and effectiveness can vary based on the quality of the cable and the power output of the adapter being employed. Some USB A adapters might not provide sufficient power output to charge the iPhone 12 Pro optimally, leading to slower charging speeds or even a failure to charge altogether.

On the other hand, USB C to Lightning cables are designed to leverage the higher power delivery capabilities of USB C technology. If this type of cable is successfully charging your iPhone 12 Pro, it signifies that your iPhone's charging circuitry is functioning correctly, and the issue lies with the USB A cable or the adapter you're using.

So basically what I got from this is your iPhone most likely updated. Most likely a push to buy their newer and more expensive type-c charger. I had the same thing happen to my brand new 14. One minute it charges with usb-a but after a certain update it stopped accepting my charger knowing full well it could charge it, just like it does older iPhones with an older update and get this even the same model IPhone but with the iOS 16 version it shipped with and it still charges. My AirPod pros still charge on this charger. Simply put apple doesn’t want anyone using usb-a anymore. and like always, are willing to do anything to accomplish this your not the only one it’s just at this point most people have usb-c already or some form of wireless charging and just assume the cables broken then they hear usb-c charges faster and buy that. I mean the 15 came out the box only accepting usb-c multiple people had the concern why does my usb-a not work but a crazy amount seeing as that phone actually came with a charger, …Probably for that exact reason haha. But best solution when your in a pinch and need it charged shut the phone off while it plugged into a Usb-a it’ll trick the phone long enough to get a full to mostly full battery usually works like a charm for me.