Q: iPhone 6 Plus Connecting and Disconnecting when syncing

That is not the issue the phone is connected directly to an iMac

In the meantime, this may be of help to you:

Sync your iPhone, iPad and iPod touch with iTunes using Wi-Fi - Apple Support

-Ethan

Ethan, have you read the problems people are having? I know you are attempting to help but your help does not address the issue.

And did you read the message above Ethans? And the one above that? What troubleshooting have you done so far, so I don't keep suggesting steps and have you say "tried that."

Yes and nothing you suggested nor anyone else has addressed the issue which leads to believe that the problem is an iTunes problem as the connecting and disconnecting is occurring on different Macs and iPhones. So, until Apple addresses this, the solution is not moot.

Any solutions yet? :/ i checked my iTunes and phone and they are both up-to-date. I can't back up and its frustrating because my 6s has dead pixels! I can't get it changed without backing up...

What seems to be working for me is that I changed all of my syncing cables. I tested them all. Some working for syncing while others work for only charging. Leads me to think that the cable and or Lightning chip goes bad for syncing purposes but will still charge a phone.

I have this issue between my 128GB 6+ and 15inch retina.  I can plug anything into the left USB port and experience no problems, but if I plug my iphone in, it freaks out(constant connect/disconnect symptom). Plugging the iphone into the right usb port, and it works fine. At first I thought the USB port might be the issue but then I realized other devices worked fine on it.

So I tried turning the macbook off and on to see if that would resolve the issue, and no luck. I then turned the phone completely off and on again, and attempted to plug it in to the left USB. This time it worked fine. It's such an odd issue, and I consider the issue to be in the phone.

it's still a recurring issue though, if I want to connect my phone to my computer I turn the phone off and then on again and quickly connect it.

I've read a handful of syncing issues that people seem to have with 128GB Iphones. I've had my phone randomly delete my 60GB song library twice, and reloading that is a pain.

I had this same problem, but with a different hardware setup than you.  I've got a 27inch iMac: late 2013.  Running 10.10.3.

I've got to believe there is a better work around, but I used every usb port and the only one that worked was all the one all the way to the left (if you're looking at the bank of the iMac itself).  I'd the same issue it sounds like you have; continually connecting and reconnecting.  It is now connected, stable, and charging.  I can also communicate with the device, so it's more than just power that's being transferred between the phone and iMac.

For whatever it's worth, my only conceivable reason for this is (other than it being a deficiency of either the OS or the hardware) that the intent of Apple is to not allow two iPhone's to connect to a single Mac, which may confuse the OS.  I'd expect that coding that within the OS would have been simple, but I've no clue.  Full disclosure: I've not tested connecting two phones to the same Mac, and I've got to believe someone, somewhere, has plugged in two phones to a single Mac.

And yes, I realize there is a high probability this is one of those, "that didn't help me" replies.

Best of luck.

I Connect 2 iPhones and 2 iPads to the same MacBook. 1 direct, the others through a powered hub.

Allllllllrighty, so after trolling the internet for a few hours I found this thread to see if it would help solve a similar problem I was having with my iPhone disconnecting while importing photos/videos from an iPhone 6 to the Photos app (and Image Capture as well) using my iMac 27" i7 (mid-2010) running OSX Yosemite 10.10.5.

I tried multiple suggestions in this thread and here's what worked for me for what it's worth:

1) Disconnected Time-Machine backup

2) Restarted the iMac

3) Restarted the iPhone

4) Unplugged ALL USB ports

5) Plugged the iPhone (via Lightning cable that came with the phone) into the USB port that sits right next to the Firewire port (or, the USB port closest to the center of the iMac for those of you who might have newer models than myself)

Boom. Worked like magic. I have no idea what part of this series of steps actually affected the disconnect issue for me, but it did indeed work. Also having tried all the USB ports, I noticed that the USB port closest to the center of the computer was the one that was significantly faster rendering preview images before importing and the only one successful at completing the import.

Holey Moley I hope this helps one of you out, because this was such a pain-in-the-butt issue for me.

With older Macs the first USB device that "asks" for power gets 1 amp, all power-using devices that are connected after that get 1/2 amp. So your time machine drive was probably getting the 1 amp, and the iPhone only got 1/2 amp, which is marginal. When you disconnected everything and restarted the Mac the iPhone was the first to connect, so it now gets 1 amp. The alternative solution is to get a powered hub that can supply 1 amp per port.

Ahhhh, I see. That's really useful knowledge! Thank you!

I had the same problem.

I couldn't import ANYTHING without my iphone disconnecting. Didn't matter if I used Image Capture, Photos or Lightroom.

Thank GOD I did not do what Apple suggested and restore my phone as a new phone.

I simply went through the pain of deleting every photo from my iphone. Something was indeed corrupted in the iCloud restore I had done when I first got the phone.

Everything imports like a champ now.

Remove all usb devices connected to your computer and restart your computer

Open Itunes (but don't connect your iPhone yet)

Make sure iTunesHelper.exe/iCloud.exe services are running (check in task manager). If not, check antivirus software is not blocking them. If you make any changes to bring the services up, restart computer again, these services should start normally I think.

Turn Off iPhone

Connect iPhone to your computer

Now Turn On iPhone

This worked for me!!!