Summary: "USB Accessories Disabled. Unplug the accessory using too much power to re-enable USB devices" is a very common problem Mac users may encounter. This article will explain some of the reasons why this error occurs and at the same time provide some fixes accordingly.

Many Mac users have reported that an error "USB Accessories Disabled. Unplug the accessory using too much power to re-enable USB devices" appears when they plug the keyboard, external hard drive, camera or even iPhone to their Mac. The problem is, even after they unplug those accessories and plug in other devices, the error still pops up. If you encounter the same problem, what can you do? Here 7 useful solutions to fix USB Accessories Disabled will be provided to help you solve the problem.

USB Accessories Disabled




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1. Reduce bus-powered devices connected to your Mac

Bus-powered devices refer to devices that get power from the device that they are plugged into. In this case, your Mac is connected to one or more bus-powered devices that are taking too much power from your Mac. Thus one possible solution is to reduce the amount of bus-powered devices connected to your Mac. Make sure the USB accessories connected to your Mac have been charged already or use them as self-powered devices instead of being powered by your Mac.


2. Switch to a different USB port

USB 3 ports can provide up to 900mA of power while the maximum power given by a USB 2 port is 500mA. With a USB 3 cable, your USB 3.0 device can use up to 900mA of power, but if it is connected to a USB 2 port, it will only get 500mA of power.

Macbook USB Port

You can check the USB port and USB power used by your device by checking the System Information. To do that, click the Apple menu icon > About This Mac > System Report. Select USB in the sidebar to view the information about your USB accessories.

Select a USB port of your MacBook or iMac to view the USB devices connected to it. You can check the USB power of each device.

Current Available: The default power provided by the USB port.

Current Required: The power needed by the connected USB device.

Check USB Power Information


3. Get a different cable

Sometimes, USB accessories are disabled because of a faulty or counterfeit USB cable. If your USB cable is certificated or it is damaged, the "USB accessories disabled" error is triggered. Just try another cable till you are sure the cable is fine.


4. Reset SMC

SMC (System Management Controller) is responsible for the physical part of an iMac/MacBook, including battery management, USB accessories connection, etc. A reset of SMC is proved to be one of the most effective to stop USB Accessories Disabled error on Mac.

The steps to resetting SMC are varied by the models of the Mac computer. Read how to reset SMC on Mac.

After your Mac is restarted from SMC reset, plug in a USB device and see if the USB Accessories Disabled error is still showing up.


5. Reset the PRAM/NVRAM

PRAM (Parameter Random Access Memory) and NVRAM (Non-Volatile Random Access Memory) are both used to store system settings on Mac, such as sound volume, display resolution, startup disk selection, time zone, etc.

You can also try to reset PRAM/NVRAM to fix the USB issues.


Step 1Immediately hold and press Command, Option, R, P keys when turning on the Mac;

Step 2Hold the keys for about 20 seconds and the computer will restart automatically;

Step 3Release the keys.

After resetting PRAM/NVRAM, all settings on Mac will be refreshed to default settings. Possibly your Mac won't show that the USB device is using too much power.


6. Update your Mac

Some external devices might be not compatible with the current macOS on your computer. In that case, you'd better update your Mac to the latest version. Open the Apple menu, click System Preferences > Software Update to check if there is a new version available. If there is, get the latest update.

Software Update on Mac


7. Make an Apple Store appointment

If your Mac keeps pops up with the "USB Accessories Disabled" error after the above solutions, maybe the problem is deeper inside the device and needs to be handled by the professionals. You can make an Apple store appointment and take your Mac to an Apple store for help.


Step 1Visit Apple Support.

Step 2Select the device you want to fix.

Step 3Select a topic.

Step 4Click on Bring in for Repair.

Step 5Enter your Apple ID and password.

Step 6Select a location.


Hopefully, you can fix your USB accessories problem after trying the above solutions. Feel free to write down your comment or contact us if you have more questions.