Mac computer's USB ports stopped working or not working at all, how to fix?
USB connection nowadays is one of few main connections, that used basically everywhere, starting from input devices, such as keyboard and mouse to external storage and output devices, such as printers or even speakers and/or headphones. While USB port is used for wide range of devices, inactive port might become a huge headache. However, first of all you should ensure the problem is within your Mac's USB ports, the easiest way would be to try few separate devices within same or all connectors.
Also ensure the cables are in a proper condition, this means you can't find any damaged, fried spots. If the results with separate devices and cables are same - they do not work, there probably is some problems with your Mac's USB ports, rarely users reports about this disappointing situation, additionally, this is not a model specific problem. This means, you may encounter with this frustrating situation on any version of Mac computer, whether it is MacBook, MacBook Pro, MacBook Air, iMac, Mac Mini, or Mac Pro. Despite the fact, that this problem seems like an hardware issue, there few methods, that may fix your problem without replacing the port or even without performing a fresh installation of mac OS. You should try to reset few built-in controllers first, due to this reason we will determine methods which modules you should reset and the method how to do it.
Table of Contents:
- Reset SMC to solve randomly occurred USB port problem
- Reset the NVRAM or PRAM on your Mac
- Additional tips while experiencing USB port issues
Reset SMC to solve randomly occurred USB port problem
If you're sure the devices connected via USB are working properly, ports are clean and connection is tight, the first method to solve your problem would be to reset System Management Controller (SMC). SMC controls computer power consumption, battery charging and functionality, thermal and fan activity, GPU and video mode functionality/video output, sleep/wake modes and led lightning management, and other hardware functionality. To reset this controller on MacBook, MacBook Pro and MacBook Air, begin by shutting down the computer and connecting a power adapter. Next step would be, to hold down combination of Shift, Control, Option, and Power keys for a few seconds, observe the power adapter light, when it blinks or changes the color, release the combination. Finally, boot your computer in a usually way by clicking the power button. After SMC reset your USB ports should work properly again, test each and all of them. Detailed information how to reset System Management Controller on all version of Mac computers and most common issues related to SMC you will find in this article.
Reset the NVRAM or PRAM on your Mac
If resetting SMC could not solve your USB related problem, you should try to reset the NVRAM/PRAM. The Parameter random-access memory (PRAM) and Non-Volatile random-access memory (NVRAM) stores information about various USB components, such as keyboards, mouse, trackpad and various other, resetting them may solve your problems. To reset NVRAM/PRAM on your Mac, simply restart it, when computer starts booting hold down the combination of Command, Option, P, and R keys. Keep holding the combination until you hear the startup chime again. Additionally, screen may flash as well. Release the buttons and let your Mac boot as usually. Once you computer loaded completely, the USB ports should be working, test each and all ports with few separate devices.
Additional tips while experiencing USB port issues
- In case only one port stopped working properly, while you may use devices connected to any other port, you should ensure the port is clean and connection is tight. Also, if you're sure the port is in good condition and resetting the SMC and PRAM/NVRAM couldn't solve the issue, you may consider about avoiding to use this particular port and use some USB hub connected to any of functional ports, or you can launch the Apple's built-in hardware diagnostic tools, to check if there is any issues with hardware.
- If your Apple computer had a contact with any kind of liquid, you should immediately shut down and disconnect from the power adapter, clean and dry out the device to prevent any permanent damage, for example the liquid may destroy some of computer's components immediately or result in loss of hardware functionality, like USB.
- In case some USB devices work on your computer, while other don't. You should check the device's compatibility with the version of Apple production you're connecting. Some of devices, rarely requires specific hardware drivers from the manufacturer to achieve it full functionality, or rarely to work properly (special use devices, modern scanners, etc.)
- If there are any firmware and operating system updates available, install them, in a reason updates are usually released to fix some bugs and various hardware and software glitches. To check the available updates on Mac computers, launch App Store application, select the Updates tab and check if any exists. It is recommended to create a backup of hard disk before updating the operating system.