Chosen Solution
I’ve been having this issue for a while with my iPad Air 2: When I plug it into my MacBook, it will act as though I am plugging it in and unplugging it rapidly, and will not stay connected long enough for me to sync or backup with iTunes. My iPhone has connected perfectly until today, when it started doing the same thing as the iPad. All other USB devices work fine, and my iPad and iPhone both connect with the windows computers at work just fine. I’ve tested with both USB ports on my MacBook, and with several known working cords, both Apple branded and not. I’ve done a lot of searching, and haven’t found any definitive answers or solutions, but today I thought I would try something. I use Windows 10 in VMWare on my laptop for work (and yes I made sure it wasn’t running before trying to sync to make sure that wasn’t causing the connectivity issues). But today I opened Windows on my MacBook, and when I plugged in my iPad I told it to open in Windows, and voila it connected to iTunes in windows fine and stayed connected. This leads me to believe it is some sort of software issue on the MacBook side of things. I even tried closing itunes and just plugging my phone in to charge, and it again acted as though I was continuously plugging it in and unplugging it, but stayed connected in Windows. Is there something I can do to correct this? I thought it might be an iTunes issue, but since it wouldn’t even keep my phone connected enough to charge without iTunes open, I’m assuming it’s an OSX issue. Any suggestions would be greatly appreciated!!
You need to reset the privacy settings in IOS, then it will recognised again. If you have not connected your iPhone to your computer in a while and the computer was updated with new software, there could be some trust settings issues. In order to check and resolve this issue, Open your iPhone, tap on Settings > General > Reset > Reset Location & Privacy.
Sometimes, the issue is purely a software one. Occasionally, there are problems with usbd daemon programme, which is the root of the issue with the iPhone. A possible solution to this problem is to open Terminal.app (Applications -> Utilities -> Terminal) and execute the following command: sudo killall usbd . It will kill the programme and it will immediately relaunch. You will need to provide your password. Please note that the password will not be visible, it is normal. If it does not work, try entering a different command in Terminal: sudo killall -STOP -c usbd . Once more, you may need to present your password
I also had this problem with my iPhone 6 and MacBook Air with an original Apple cable that works fine when charging normally, so it had to be something with the computer. I chatted with Apple customer support and they told me to update to the newest OS-X and do an SMC reset on my MacBook Air. It’s easily done and did the trick for me. They also told me I could try an NVRAM reset, but this was not needed in my case. Hope this can help someone!
After trying all the recommended fixes for this issue in all the different forums I could find (new cables, privacy setting resets, full system reset etc) I still had the problem so I have come up with a work around. I now plug all my devices - iPad, iPhone - in to a USB multiport and then connect the multiport’s USB cable to my MacBook air. Problem solved! I’m using the Belkin 4-Port USB 3.0 Powered Hub! - Which I’ve plugged in to power as well as to my Mac. Basically, letting the Hub power my devices Vs my Mac.
Mine always does that. I think it’s because battery is not charged enough. I can only connect successfully when my MacBook Air battery is 100% even then it takes a second try :) . I think it doesn’t get enough energy from USB when battery is not charged enough. So it keeps try to get enough voltage and fails. I haven’t tried but maybe a shorter cable would fix our issue. Try when your battery is full. You’ll see it connects successfully.
After a long time with this issue, my conclusions: some of us are having this issue because of a board design issue, current demand from our USB device(iphone/ipad) is higher than mac USB can provide, as a result the port fails.You will see this issue more frequantly when your device pulls more current - when it has low battery and tries to quick charge or when you use a high demand devices(ipad/Plus/Max)when only the SUDO KILL command helps you have the 1 & 2 issues i wrote.
I have the same problem and had not been able to resolve it. When I connect the very same iPhone with the same cable, through a USB 3.0 hub connected to the MacBook the iPhone gets connected instantly without any issues.
@James Tompkins, it lets you type the password, it’s just NOT shown to you as a security measure. Just type your password completely and press enter
Well, crap. I switched from my trusty old 15” mid-2012 Macbook Pro to a 15” mid 2015 Pro. I ran into this same infuriating issue with my iPhone XS. I actually have two 15” 2015 Macbook Pros on hand at the moment, and it’s doing it on both. Running the sudo killall -STOP -c usbd command fixes it, until I reboot or wake the computer as others mentioned. Plugging in my 6S Plus is better, it usually works, but still does it occasionally on one of them. You can bet Apple will hear from me… Update (12/17/2019) Mine is working now. Apple serviced my mid-2015 15” MacBook Pro, replacing the motherboard and I/O board. (so they said, it still has the same serial number) I did notice one thing before I sent it in. As long as it was running macOS Catalina, I had no issues. Downgrading it to Mojave brought on the issues. Upgrading back to Catalina made it go away. However, it was not strictly software specific. The Genius Bar tech replicated it with ease using a triage drive in store. Once I got the laptop back, I reinstalled Mojave out of curiosity. I was still able to reproduce it a time or two, but it was much more reliable. Now that I’m back on Catalina I have no more issues. I now like this laptop except for the pathetic keyboard feel.
You may have a USB port issue. Have you tried the other port as well as a different Lightning cable? To test the system this device is quite useful: USB Mini Voltmeter
I solved that problem by a slightly change cable position …. :)
i kept my phone connected to my mac and turned it off for 5 minutes before turning it back on and it stayed connected!
I have the same problem, and had not been able to resolve it. When I connect the very same iPhone, with the same cable, but trough a USB 3.0 hub connected to the Macbook, the iPhone gets instantly connected without any issues.
If you connect through an Apple USB wired keyboard USB port it works fine! If you don’t have a USB port in the keyboard you may be try a cheap USB hub.
WOW. This actually worked for me too! I had an OLD hub lying around… worked first go. Frustrates me that I had to go through everything else, and this ended up being the solution!!
I had 2 problems. Your iPad could not be activated because activation server cannot be reached. Try connecting your iPad to iTunes to activate it, or try again in a couple of minutes." “If this problem persists, Apple Support at apple.com/support.“ERROR 9 trying to update or restore it in system restore. I tried virtually everything to no avail trying to restore an old iPad 2 with both the activation AND error 9 problems. finally i took the advice of using a USB hub AND force terminating usbd before iTunes finally recognized the iPad and starting restoring it. PHEW.
I was able to solve this same problem with my iPhone 6s by restarting the phone. It was not the solution I was expecting, but after trying different chargers, computers, and USB hubs, this is what ended up working.
When you are running a VM, make sure you have your iPhone connected to your Mac explicitly.
Same Issue lasted for 2 yrs… No way to solve it but… When i went to the apple store to change the battery of my mac (15”, mid 2015 ), and they changed all the top case including battery keyboard and touchpad, the issue has gone. So for the ones that have this problem I suggest to change all the topcase, that include the battery. Bye!
I’ve had this issue on both USB ports of my mid-2017 Macbook Air. It usually “settles” after a bit of time but not without much frustration, often when I really need my battery charged (when my iPhone 7 is at 2-3% especially.) It’s really bothersome, but I’ve just tried resetting the privacy settings and I hope that will help. I’m also using the original Apple charger included with my phone, so I’m not sure that’s necessarily the culprit.
Excellent! I have had this same issue with iPhone 7s and now with iPhone Xs for years and this has solved the problem! Thanks !
This didn’t work for me. I’ve updated everything, but I still have the rapidly connecting/disconnecting issue. Very frustrating!
I’m trying to run the Kill commands and when I do it says password with a little lock… but it won’t let me type my password? Anyone know how to do this? I can’t plug my new phone into my new MacBook :(
I have tried literally everything I read on internet and still couldn’t fix it, So I turned off my MacBook and turned it back on while iPhone was still plugged in, it connected and stayed connected! When I unplugged it and tried it again it kept doing the same connecting/disconnecting thing. So I would suggest just restart your MacBook while iPhone is still plugged in USB port and see if it solves the issue.
For some reason it seems to connect sometimes and stay connected at the most random times… and everything else I use works fine with the port so I know it’s working correctly.. but what you suggested seems like a great idea! I’m going to give that a try.. thanks !
It’s connecting but once it gets to the Itunes part where it tells me to trust this computer for itunes, the pop-up will not show in my iPhone. I will press continue and wait for my phone to pop-up something but nothing comes up.
I tried the command: “sudo killall -STOP -c usbd” but when I turn it off or close the mac and connect the iphone again, it happens again. There is no definitive solution? I have a MacBook Pro 2015 and I tried with iPhone XS and iPhone 7 plus.
if sudo commands does not work please try to reset NVRAM ref: Fix iPhone keeps connecting and disconnecting from Mac
I have the same issue when I use a external USB wireless mouse. After I unpluged everything, the iphone stay connected with no problem.
I did two things simultaneously. i did the shutdown, hold power button on for 10 seconds, then wait 4 seconds, then press power on a gain to restart, but I also changed to a non-hubbed USB port ie I directly connected to computer.
I have noticed that this issue is linked with Charging. When I remove the charger, then there is no disconnection.
May 2 2021 I have same problem, but when I connected an external usb hub and connect my iPhone to the hub, the MacBook automatically detected the iPhone.
Whenever we have this kind of problem what we should do is reset the network setting to defaults. After that set a strong network security key and update network adaptor drivers too. And yes keep audit and manage your virus removal software too.
