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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

Apr 28, 2021 7:24 AM in response to MélodyH

This was one of my struggles and I searched several times for an answer. One comment was finally correct! It’s because the battery is too low! If my phone was under 50% then it would essentially freak out and keep connecting and disconnecting instantly. I think it’s because it was struggling to charge and connect to the iMac. So after it’s charged to a good amount, mine does not do it anymore. I hope this helps other frustrated people solve it. 🤞🏻❤️

Apr 29, 2021 11:05 PM in response to MélodyH

I FIGURED IT OUT - so I have a 2015 MacBook Pro and an iPhone 11 Pro Max. Both USB ports gave me the rapid disconnect/connect, and was so frustrating. Tried EVERYTHING - reformat everything, reset everything, BUY A NEW IPHONE, yet nothing worked. THen work gave me a new iPhone SE and it didn't have an issue.


So I thought, maybe it's to do with the power draw/output on the USB port vs a powerful iPhone!


So I got a Ethernet USB adapter that has a USB port on it, and plugged my iPhone it that way.


IT WORKED - no more rapid disconnecting! So it's not an elegant solution because Apple are Apple and we love dongles. But at least I can finally backup and sync my iPhone!


Next problem to sort out: Album Art and songs repeating the last 30s!

Aug 5, 2021 2:54 AM in response to MélodyH

Someone had this answer above but it wasn't explained well so like most of you I scrolled by. I tried in this thread and it didn't work. But this did! Open the Terminal app from Spotlight (Command+ Space) and enter the command sudo killall -STOP -c usbd

Yeah, it's that easy.

This will pause the usbd process. Now, connect the USB cable and check if the iPhone is still charging on and off rapidly.

I've had this problem for YEARS. I'm so glad it's fixed!

Sep 24, 2021 4:16 AM in response to MélodyH

Same with iPhone 12 mini (15.0) on M1 Mac (11.6).


Intermittently disconnects from Finder and Image Capture, sometimes mid-sync.


Important:

• works fine on an old MacBook Air with macOS Catalina, same cables.

• other iPhones / iPads all work fine on the M1 Mac Mini with the same cables.


• tried different cables (USB, USB-C) and ports

• only original Apple cables, undamaged

• tried without USB hub

• tried rebooting all devices

• tried resetting the privacy / location settings on iOS, trust computer again.

• tried killing the usbd process

• tried creating a new user on the Mac


In System Preferences -> Network I found a couple of Thunderbolt bridges and "iPhone USB" devices that all had red or orange indicators. I deleted them all an now it seems to work.



Oct 10, 2021 6:51 PM in response to MélodyH

This worked for me (going to network in system preferences on computer, click on iphone usb, uncheck box that says disable when needed) when nothing else did. iphone xs max with ios 15 connected to 2015 macbook pro 15 inch running big sur 11.5.1


For the last year nothing else corrected the rapid on/off when phone was connected via usb to computer. This fixed it.

Oct 22, 2021 1:47 AM in response to nk5.2

Thats true, #AppleCare doesn't seem to care at all, every supposed trick here is just guess work and not an actual solution, people tried their best to resolve among themselves, meanwhile the apple admin idiot who manages this thread probably doesn;t even open this page to actually try and give an f...! All while launching new crap non stop...

Nov 7, 2021 7:10 PM in response to MélodyH

I also had this problem for a long time but trying solutions posted so far such as stopping usbd only worked sometimes. I now have the suspicious the root cause might be that this rapid connect/disconnect only happens when the iPhone is <100% charged so that the iPhone is using the USB connection with PC/laptop to charge itself while trying to use is as real communication link at the same time. Bringing the iPhone 100% charged seems to work OK although the link still flips a few times before settling down. Best would be if anyone knows how to stop the USB connection being used for charging temporarily from PC/laptop or iPhone side.

iPhone connects and disconnects from Mac

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