iPhones won't mount in iTunes - Mac restart needed

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iPhones won't mount in iTunes - Mac restart needed

I'm having the problem long described in iOS: Device not recognized in iTunes for OS X - Apple Support.

Our iPhones stop being recognized by iTunes 12. I've followed the recommended fixes, and the only thing that works consistently is to reboot my Mac. Logging out doesn't help. Switching cables doesn't help and when it happens it affects all devices, not one particular device. It seems to happen after I get "iphone no longer connected' messages.

It's darned frustrating. It doesn't seem to be an extremely common issue, so I wonder if there's a hardware problem somewhere (Mac motherboard? USB hub?).

I also suspect bugs related to 'Trust this Computer' but resetting Trust settings didn't help.

Anyone have ideas on how to debug?

Only thing I can think of is to try going without the hub for a while and switch to wifi sync and separate charger.

Any other ideas?

Posted on Dec 25, 2014 6:06 PM

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Answer 1

jfaughnan Author

Level 3

886 points

Dec 25, 2014 6:08 PM in response to jfaughnan

I should add I'm on Mavericks. I have VMWare Fusion installed but it's rarely used.

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Answer 2

jfaughnan Author

Level 3

886 points

Dec 25, 2014 7:35 PM in response to jfaughnan

Sounds like this thread is about the same problem:

Re: itunes 12 will not recognize iphone

Alleged cause is a bug - usbmuxd isn't closing its file descriptors. After 2-3 days errors pile up, typically with recurrent "Trust This Computer?" loops (which is what I see). In this case the "Trust this" is a misleading message related to usbmuxd locking sockets.

Killing usbmuxd process in activity monitor didn't fix the bug for me, I still had to reboot. I noticed though that I had a Tech Tools Pro daemon running that I didn't expect and I have uninstalled that. I'll try killing ubsmuxd next time this happens.

We very much need iTunes 12.0.2+

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Answer 3

jfaughnan Author

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886 points

Dec 25, 2014 8:28 PM in response to jfaughnan

Kelly Wilkerson recommends killing both usbmuxd, and, for wifi sync, mdns.

http://deciphertools.com/blog/2014_10_222_no_devices_showing_in_itunes/

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.usbmuxd.plist

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.usbmuxd.plist

and

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

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Answer 4

jfaughnan Author

Level 3

886 points

Dec 30, 2014 11:13 AM in response to jfaughnan

We have a lot of iOS Devices that sync to one iTunes instance, and we have been charging off a USB hub. So the usbmuxd bug is killer for me.

I'm now scheduling a nightly restart to clear my Mac: OS X Mavericks: Schedule your Mac to shut down or go to sleep automatically. I used to do that sort of thing in the old windows days.

I'm also purchasing a 6 port USB charger so I reduce the number of times I connect an iOS device to iTunes; much of the time it's just for charging.

PS. There was a similar usbmuxd bug in 10.6: Mac OS X v10.6: iOS device not recognized in iTunes after restart - Apple Support. I might try those old measures too.

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Answer 5

Jan 8, 2015 8:47 AM in response to jfaughnan

jfaughnan wrote:

Kelly Wilkerson recommends killing both usbmuxd, and, for wifi sync, mdns.

http://deciphertools.com/blog/2014_10_222_no_devices_showing_in_itunes/

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.usbmuxd.plist

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.usbmuxd.plist

and

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

I'm glad it's working for you (and thanks for plugging my article 🙂) I should probably start finding the similar reset commands for Yosemite when I see it happen on that machine!

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