I have an issue when I plug in my iPhone 11 Pro Max into my MacBook Air 2017. The issue is that it starts to charge for like 1 second, disconnects for 5 seconds, and then loops like that. Do you think the issue could be with the port or the software?

I am running macOS Catalina 10.15.5 and iOS 13.6.

Edit: It was a lightning cable issue. Other newer lightning cables work fine.

  • 1
    Have you made sure there’s no dirt or other interfering substance down inside the iPhone’s Lighting port? Aug 10, 2020 at 16:05
  • @DavidSupportsMonica My Apple Watch is able to charge just fine from either port. The iPhone cannot charge from either port of the MacBook Air. Aug 10, 2020 at 16:07
  • One more thing, the iPhone is also able to charge just fine from other plugs. Aug 10, 2020 at 16:08
  • 1
    The iPhone charges fine when using the same cable on other devices as well as the wall? Can you test other iOS devices with the same cable on the same MBA? The symptoms you're seeing are usually indicative of a bad cable or USB port that can't output the required power to an iOS or iPadOS device.
    – fsb
    Aug 10, 2020 at 16:12
  • Meant to say that using the same cable works fine on other plugs, battery packs... Aug 10, 2020 at 16:29

1 Answer 1


The issue is that it starts to charge for like 1 second, disconnects for 5 seconds, and then loops like that.

Dirt or another containment in the port isn't going to cause a loop that cycles in a regular intervals. When you connect an iPhone to a MacBook, there is a charging negotiation - normally, the USB spec is for 5V @ .5A, but the MacBook can "boost" the available charge up to 2.5A - it has to "ask" for it, however. That "loop" that you're seeing is a connection, an ask and a disconnect and then the device trying again.

It could be a couple of things...

  • You have an issue with your port not being able to supply enough power to the phone
  • You don't have sufficient power on your USB bus
  • There could be a hardware issue - either with the MacBook or the iPhone

If you can charge your phone correctly otherwise (i.e. with a regular USB power adapter) and your USB port functions normally, start with an SMC Reset. If that doesn't fix it, try Safe Mode by holding ⇧ Shift while booting. But, to be candid, I don't see that having much effect, if any at all. Charging is not handled by the OS, but by the firmware on the SMC chip. In this case, ensuring your firmware and software is fully updated would be the next best thing.

Lastly, you want to ensure that your connectivity is good - avoid cheap, knock off cables and connectors. I assisted someone just yesterday who insisted against my advice on using one of those 5-way USB spider things that has all the different USB connectors on one cable she picked up at a trade show; It fried her Dell XPS' charging ports. Use good quality cables from trusted brands (I like Anker personally). Saving $5-10 on a cable simply isn't worth it.

If it is the hardware (either phone or Mac) you might just want to avoid charging with your Mac and stick to the wall adapter. To fix it would require replacing logic board(s) and it may not be worth the expense. If it's under AppleCare...well, that's a different story altogether. You'll have to make the call to see if it's worth the AppleCare incident for this issue.

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