I’ve been scanning through the Apple Discussions, but I can’t find the same combination of issues/symptoms.
If I’ve missed something, I appreciate your forbearance in directing me to a thread I may have missed
Background
My iPad, when I plug it into my iMac, does the repeated chiming/dinging thing (keeping it from charging) and it doesn’t show up in iTunes. I’ve been using the original USB connection cable and thought maybe the cable was bad, so I tried a third party cable and an iPad dock with both cables. No change. So then I did a bunch of other things in the course of my troubleshooting, thinking maybe it was a software problem. (I put the iPad into Recovery Mode and tried restoring it to factory settings, restarting the pad and the computer, and following other bits of advice based on the error codes I was getting in iTunes [ex: 1647, 19]. The chiming stopped, the iPad showed up in iTunes, and I could begin the restoration process, but I would always eventually get an error message that the computer couldn’t communicate with the device.) After trying this and that, I had nothing but an iPad stuck in Recovery Mode that I hoped was charging when I used the wall charger (it didn’t chime at all). I was able to use Dr.Fone on my MacBook Pro to get my iPad out of Recovery Mode. Turns out, when I plug the iPad into my MBP (using the original cord and/or dock), there’s no dinging, and the iPad charges, and it seems to be all find and dandy.
So here’s my question
What might be wrong with my iMac?
I can plugin and sync my iPhone, none of the other USB connections are bad (SuperDrive, printer, cables to connect an iPod), and it doesn’t matter which USB port I plug the iPad connector into, I get the same dinging. And yes, I’ve done the rebooting thing, checked for software updates, and repaired disk permissions.
Device Specifications
At home we have an iMac (21.5-inch, Late 2013; 2.9GHz quad-core Intel Core i5), and my work computer is a MacBook Pro (13-inch, Mid 2012; 2.5 GHz Intel Core i5). I keep them updated myself, so both the iMac and MBP are running Yosemite (10.10.5) with iTunes 12.3.1.23. I sync my iPad (3rd Gen WiFi, 30-pin connector) and iPhone (5c, lightning connector) with my user account on our home computer (iMac), and they are both running iOS 9.2.