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iPhone connects and disconnects from Mac

Hello,


When I plug in my iPhone to my Macbook pro, it repetitively connects and disconnects. Therefore I cannot charge my phone through my computer anymore.


I own this iPhone since decembre 2018, and this issue only appeared this week. However when I plug in my iPhone to a wall outlet, it charges perfectly. I also noticed that there is a lag time before my phone starts charging when connected to my Macbook (before disconnecting right away, and then reconnecting etc).

I tried to connect my iPhone to both USB ports of my Macbook, with many different Apple lightning cables and also my Anker cable (MFI certified), but the issue substains. I plugged in my mother's iPhone 6 to my Macbook and it charged perfectly. I plugged in my iPhone to my brother's former Macbook pro (15" from 2008) and my iPhone could charge normally.


Here everything I tried to resolve this issue (which failed by the way) :

- I shut down and turned on my computer and my phone.

- I reseted location and privacy of my phone (Devices rapidly disconnect/reconnect - Macbook Air Mid 2013).

- I also restored my phone.


Could anyone tell me a solution?


I specify that I have a 256Go iPhone X under IOS 11.2.5 and a 13" retina Macbook pro (mid 2014) under High Sierra 10.13.3.


[Re-Titled by Moderator]

iPhone X, iOS 11.2.5

Posted on Feb 10, 2018 1:34 PM

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Question marked as Best reply

Posted on Aug 28, 2019 4:20 PM


Sep 11, 2018 8:27 AM in response to MélodyH

Connect your iphone to your Mac.

Go to Activity Monitor --> Search for usbd --> Force quit it.



The above worked for me. To add a bit: You click on the upper right of your screen where there is a magnifying glass and search "activity monitor." Keep "CPU" highlighted. Type "usbd" into the search box. Now plug in your phone. It'll connect, reconnect, connect, reconnect and so you have to be quick and double click on "usbd" even though photos and itunes keeps popping up. then once you've successfully double clicked "usbd," click on "quit" which takes you to a screen that says "force quit" and click "force quit."


I also took the recommendation of going to my iphone and settings-->general-->reset-->click on reset location and privacy.


I did both and it worked.

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276 replies

Nov 2, 2019 6:59 AM in response to la3

Spent three days at the Apple store. Finally a tech deleted my phone backups and created a new one and that's all it seemed to take. Maybe it was some other things we'd tried previously, but this seemed to work right away. There seemed to be some conflict with iTunes and Photos bumping into each when I connected. I know it sounds too easy, but give it a try. It worked for me.

Nov 6, 2019 6:17 AM in response to YashYY

Update:


The problem persists, albeit seemingly less severe. The iPhone doesn't connect and disconnect as viciously as before and after a few back and forths, it stops. But, I still have to open terminal and enter that command for it to calm down.

I should note that I tried deleting all the backups on my computer as well as deactivating Photos from automatically opening (because mentioned in previous comments as helpful).


Result:

Solution did not work. Problem persists.

Nov 26, 2019 3:03 AM in response to Arashk.B

That is genius Arashk B. It’s a very frustrating problem that a lot of people are experiencing. Using my troubleshooting abilities developed through years of computer programming I had arrived at the same conclusion. I had determined that it’s a software based problem because the lightning cables that people are using are working everywhere else and the USB ports on their MacBooks are working with other USB devices. So there’s a bug in the OS (or it’s written that way) so when the power is low on the attached USB device MacOs will automatically send a disconnect to the USB port. Then the OS does what it was designed to do: it detects there’s something in the USB port and connects again! I’m communicating through Apple and some of my IOS app developers to see if there’s a work around.

Dec 8, 2019 9:50 AM in response to MélodyH

This has happened to me so many times and I could never pinpoint the variables until this super helpful post! Thank you to all that have weighed in on this.


Here's what consistently works for me nowadays with my iphone7. If my phone is charged above 50% and my phone disconnects, then I need to delete the "usbd" process from the Activity Monitor on the receiving computer. If my phone is charged below 50% (and that battery indicator is not always that accurate), then charging my phone works. I did not realize that the power level on my phone would make a difference, but it does.

Dec 11, 2019 6:55 PM in response to MélodyH

I also am having this issue when connecting both my iPad Mini 4 and iPhone XS, and killing the usbd process on my Macbook Pro also solves it.


But here's an unexpected twist: I only see the problem when using the lightning cables from those devices. If I use a lightning cable from my iPhone 6, it works fine every time, without having to kill the usbd process.


Can anyone else reproduce that? If so, maybe it's being caused by a characteristic of newer lightning cables?

Jan 17, 2020 11:20 PM in response to MélodyH

I am having same issue with iPhone XR rapidly connecting and disconnecting when I plug it via USB into my MacBook Pro (Retina, 15-inch, Mid 2015).


It is interesting to read about all of the solutions that worked, worked only once (or sometimes) or not at all.

It seems like there is not a definite solution that would work for everybody.


Someone mentioned that we pay a lot of money to Apple for their products. So true. We make them soooo rich !!!

So in return, we all deserve things to work together without the problems we're experiencing and that make us scratch our heads and waste our time trying to fix these problems.


At one of his famous keynotes, Steve Jobs said: "It Just Works".


That's what we pay for, that's what we expect and that's what you, Apple, need to get back to.


So Apple folks, please figure this problem out and give us the proper fix.


Thank you,


Bronco Hyrman

Apple User since 1994

Jan 29, 2020 10:57 AM in response to MélodyH

In addition to what others have stated - I have had a couple of my laptops usb port get slightly loose and basically go out one didn't get loose and would not work for almost every usb device plugged into it but would on one or two... my other port worked continually for the life of those computers. SEE if it's in there firmly, try another usb port like a battery pac - and also consider the cords DO go out, even if new - I recently had two new ones go out - one after a few days and another after a few weeks.

Feb 16, 2020 1:39 PM in response to RafalPender

If you want a ton of detail, read here: https://apple.stackexchange.com/questions/382002/iphone-mac-connection-issue-and-what-does-the-usbd-process-do But the short answer is that executing "sudo killall -STOP -c usbd" from the terminal app will not require continual force quitting of usbd process. It should last until you reboot your Mac. So far, it's worked for me, but the pitfall is charging occurs at a much slower rate. Good luck!

iPhone connects and disconnects from Mac

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