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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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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
Question marked as Best reply

Aug 28, 2019 4:20 PM in response to MélodyH


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.

Mar 19, 2018 4:41 PM in response to MélodyH

I'm having this problem too, on an iPhone 7 connecting to a MacBook Pro, both with all software updates installed.


One thing I notice is that the phone very quickly flashes a pop-up ("modal") asking if I should trust this computer or not. But it's gone before I have a chance to press "Yes". (Actually, I once got it in time, and a screen for me to enter my PIN appeared, but only for a microsecond.) The connect/disconnect also stops briefly when the laptop pops up that "A new network interface has been detected: the 'iPhone USB' network interface has not been set up. To set up this interface use Network Preferences". But no matter what I do next, the cycle starts again.


The phone connects correctly to an older iMac running 10.7.5, so I suspect the issue is with the software on the laptop, but perhaps is a cycle of each wanting to verify that I should trust the other and getting in each other's way?

Nov 1, 2019 5:24 AM in response to MélodyH

I had the same problem. My computer was a late 2014 iMac 27" 5K. Problem started with my iPhone 6 and persisted after I upgraded to iPhone Xs. Things I had tried:

  • Restarting many times both iPhone and iMac.
  • Changing the USB inlet.
  • Using a different USB cable. The problem would stop for a very short time and then return.
  • Connecting to my MacBook Pro with the same USB cable. It worked fine. Problem was with iMac.
  • Force quitting "usbd" from Activity Monitor.
  • Settings>Network> iphone USB> then uncheck the box that says "Disable unless needed"


None of the above worked. Until I contacted Apple Support today. They prompted me to enter this Terminal code:


sudo killall -STOP -c usbd


Problem stopped immediately. I restarted the iMac and things still work fine. Haven't seen how it turns out long-term, though. Give it a try.

May 31, 2018 3:29 AM in response to MélodyH

Hy everyone.

I had same issue on my iphone 6, ios 9.3.2. After searching through the web i found following solution that helped me:

You need to reset your privacy and location info and then trust your iphone with itunes again.

1. Disconnect your iphone from cable.

2. On your iphone: ->Settings -> General -> Reset -> Reset Location & Privacy (accept all things).

3. Connect your iphone back to cable. (iphone will reconnecting again, don't worry, it will be soon over).

4. iTunes will ask about trust, accept all this.

After that your iphone should stop reconnecting repeatedly and start to charging normally.

Sep 23, 2018 3:56 AM in response to rpmartins

Thanks for the tip.


However in the above scenario my Macbook was jumping from any desktop i tried to work in back to the desktop where I was running iTunes. By the time I had selected any other app (terminal included) I was thrown back to iTunes because it wanted to show me a message. I never saw this message because it got hidden behind the iTunes window. I only discovered the message after taking a guess at what was going on. So with terminal I would have had no chance to type anything, because as soon as I selected the correct desktop (where I keep terminals assigned) I would not get the time to even select the terminal let alone be able to type something into it. It would be far better if this message (regards trust) was thrown up in the notifications sidebar where it would have less influence on the behaviour of Apple's display manager. But seeing Apple have done nothing to improve the display manager with regard to the reliable positioning of apps on desktops I don't expect a change in this area either - a means to interrupt the display manager when it goes berserk - not even being able to reboot via the applet on the top left of the screen. My only solution was to log in from another computer and reboot.


At this point (remote terminal via SSH) using "sudo killall -STOP -c usbd" would have saved me rebooting.

Jun 4, 2018 5:53 AM in response to MélodyH

I have an iPhone X and MacBook Air. I have done everything and nothing fixed it. Tried this and seems right. I hope Apple figure it out and fix it in new updates, however, I've seen that people have had this problem from 2013.


Re: Why does my iPad keeps connecting and disconnecting from the new late 2013 iMac

Hey everyone,


I just wanted everyone to have the solution here that way when others experience it, they can hopefully find this solution quickly. Luckily several of you like (MrArifFikri) touched on the solution already, I'll just specify the reason for clarity.


It comes down to power, or more importantly "current". Specifically, with an iPad, USB power consumption is very finicky. So in order for the USB direct connection to your PC, USB hub, or laptop you need to make sure your iPad is charged to over 51%. This will reduce the power draw the iPad will attempt to pull from the USB connection. This should give you flawless charging and syncing capabilities. Now you can sidestep this in some cases by using USB ports on your hub, PC or laptop that are closer to the power supply, or series on the circuit board.


If your iPad is below 51%, you need to use the "cube" or power block that came with your iPad. (The smaller one for your iPhone is not recommended as it lacks the internal transformer that the iPad power block has) The reason for this is that your iPad is attempting to draw too much current from the USB connection through a substrate, i.e. the PC, USB hub or laptop connection. They are only designed to allow a limited amount of current through those connections, thus your iPad continues to "trip" the charging circuit in the device because the power draw is too low.


I hope this helps stop the "doodledee.....deeedledoo" beeping madness you're experiencing! 🙂

Sep 20, 2018 1:12 PM in response to MélodyH

I think I found a solution after much research.


On the mac, go to settings>Network> iphone USB> then uncheck the box that says "Disable unless needed"


This worked for my iphone 7


I hope this helps!

Apr 22, 2018 6:29 PM in response to Eric Myers

But I do think I solved my problem, by something similar.


On the hunch that the computer was trying to set up a network connection via the phone while the phone was trying to do something else, I went into the network settings and found that in the list of services I had an entry for "Thunderbolt Bridge." I thought it was off, because it was listed as Inactive and the configuration I could see said "Configure IPv4: Off". But to make sure it was really completely disabled I pushed the "Advanced" button to change the configuration details (after clicking the lock icon and authenticating, of course). I changed "Configure IPv6" from "Automatically" to "Manually" and saved that.


After that, connecting my phone to the laptop finally worked. I was just now able to get some pictures off my phone onto the laptop.

Sep 19, 2018 6:24 AM in response to MélodyH

If you use multiple desktops with one desktop handling photos (ImageCapture), and another desktop handling iTunes, the madness that ensues is impossible to reconcile, because the macbook pro jumps from one desktop to the other while you are trying to accept a trusted connection, and the iPhone is doing its thing - connecting and disconnecting.


Apart from the very poor/weak management of multiple desktops in OSX (vs Linux), this situation can drive you insane.


The solution is to make sure iTunes is not running when you connect your iPhone - and be on the same desktop as ImageCapture will be when it automatically starts. When you connect your iPhone remove (swipe away) all active apps so that when you get the message to 'trust' this computer you can answer it.


For me this failure to connect occurred when I must have changed from the Wifi to LAN (via thunderbolt) connection. If I changed USB port and set WiFi ON it connected without a problem. But I got curious as to why I could not connect with the first USB port, and the above solution evolved.


This said, I do not agree that Apple should be able to make changes that remove the trust that is already established between devices. It is careless and arrogant behavior to allow customers to be left stranded. The more IT savvy will be able to solve this without resorting to the 'Genius Assistants' in the shops.

Nov 6, 2020 6:23 PM in response to MélodyH

I had issues connecting my new (to me) iphone XS to my macbook pro running High Sierra (becasue I love how solid it runs). None of teh suggestions helped so I manually downloaded and reinstalled iTunes and when I did it told me I needed an extra update to make my iphone work with it. Suddenly everything started working. You can manually download iTines here - https://support.apple.com/kb/dl1977?locale=en_GB

Apr 24, 2022 4:45 PM in response to MélodyH

This error means something went wrong while establishing the connection between the Mac and the iPhone. These suggestions are largely useless - a lot of things could have gone wrong, and things like restarting the Phone or changing the cable won't fix any of them. This has happened to me twice over the past few weeks - it turned out there was a corrupted file that caused the problem. Deleting the file let the phone sync again. I don't know what the implications are for my music library - I'm a recents switcher from Android, and haven't synced anything yet. In any event, I can't think of an excuse for Apple not to have fixed this in the 10 years since it was first reported here: https://discussions.apple.com/thread/4474508?page=3


Or if not fixed, at least provide enough information to correctly diagnose the problem - I'm sure this corrupted file isn't the only cause. These reboot the machine / replace the cable / reset the phone suggestions are frankly insulting, and the reason a lot of users stopped using Windows years ago. No reason to recreate the same useless support environment for Apple products.

iPhone connects and disconnects from Mac

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