Best Products Computer Components What to Do When Your USB Ports Aren't Working Try these fixes on your PC or Mac By Jeremy Laukkonen Writer Jeremy Laukkonen is tech writer and the creator of a popular blog and video game startup. He also ghostwrites articles for numerous major trade publications. our editorial process Facebook Twitter LinkedIn Jeremy Laukkonen Updated March 25, 2020 Computer Components USB/USB-C Monitors Keyboards Mice Cards CPU Storage Laptop Bags & Backpacks Printers View More Tweet Share Email Whether you’re hooking up a USB flash drive, headset, printer, trying to sync your MP3 player, or even your smartphone, you expect your USB devices to just work when you plug them in. That’s the beauty and simplicity of USB, or universal serial bus, which is designed to allow devices to be connected and disconnected at will, often to both Windows and Mac computers, without a whole lot of hassle. When your USB ports suddenly stop working, the problem can always be tracked down to either a hardware or software failure. Some of these problems are the same across both Windows and Mac, while others are unique to just one or the other. Lifewire / Jie En Lee Here are eight things to try when your USB ports stop working: 01 of 09 Restart Your Computer Fabrice Lerouge / Getty Images Sometimes you get lucky, and the easiest solution ends up fixing the biggest of problems. And when the problem is a malfunctioning USB port, the easiest fix is to restart your computer, or simply turn it off and then turn it back on again. When the computer has finished restarting, go ahead and plug in your USB device. If it works, that means the problem has sorted itself out, and you don’t need to worry about it. A lot of things get refreshed under the hood when you restart a computer, which can actually fix a whole lot of different problems. If you aren't that lucky, then you'll want to move on to more complicated fixes. 02 of 09 Physically Inspect the USB Port JGI / Getty Images USB is pretty robust, but the fact is that these ports are wide open whenever you don't have a device plugged in. That means it's pretty easy for debris, like dust or food, to get wedged inside. So before you do anything else, take a close look at your USB port. If you see anything stuck inside, you'll want to shut your computer down and gently remove the obstruction with a thin plastic or wooden implement like a toothpick. In some cases, a product like canned air can be useful in blowing obstructions out of a USB port. Just be careful not to shove the obstruction further in. USB ports can also fail due to a loose or broken internal connection. One way to test this is to insert your USB device and then gently wiggle the connection. If it briefly connects and disconnects, then there is a physical problem with either the cable or the USB port. If you feel a great deal of movement when you gently wiggle the USB connector, that indicates it may be bent or broken off the board that it’s supposed to be connected to. And while it is sometimes possible to fix this type of problem, you may be better off taking it to a professional. 03 of 09 Try Plugging Into a Different USB Port kyoshino / Getty Images If restarting didn't help, and the USB port looks okay physically, then the next step is to figure out whether you're dealing with a port, cable or device failure. Most computers have more than one USB port, so a good way to rule out a single broken port is to unplug your USB device and try it in different ports. Plug the USB device into a few of the ports on both the front and back of your computer. If the device doesn't work in any of the ports, there's likely a problem with its hardware. If your device starts working when plugged into different ports, then the first port probably has a physical problem that needs to be fixed. It's also possible that there's a connection problem with all of the USB ports on the front or the back, which is why it's important to try more than one. 04 of 09 Swap to a Different USB Cable Chumphon Wanich / Getty Images USB cable failures are more common than USB port failures, so make sure to swap in a different cable if you have one handy. If your device suddenly starts working, then you know that the problem was a broken wire inside the other cable. 05 of 09 Plug Your Device Into a Different Computer JGI / Getty Images If you have another computer or laptop handy, then try plugging your USB device into it. This is an easy way to rule out a problem with the device itself. If your USB device springs to life the moment you plug it into your backup computer, then you know for sure that you’re dealing with a USB port problem. 06 of 09 Try Plugging in a Different USB Device Dorling Kindersley / Getty Images If you don’t have a spare computer, but you do have an extra flash drive laying around, or any other USB device, then try plugging that in before you move on to anything more complicated. If your other device works just fine, then you’ll know that your ports are in good working order. In this case, you may need to fix or replace the device that failed to connect. If your USB ports still don’t work after restarting and trying different combinations of devices, cables, and computers, additional steps to fix the problem are more complicated and specific to either Windows or Mac. 07 of 09 Check the Device Manager (Windows) There are two things you can do with the device manager in Windows to get USB ports working again. Some of the steps may be slightly different depending on your version of Windows, but the following steps work on Windows 10. Scan for Hardware Changes Using Device Manager Right-click Start then left-click RunType devmgmt.msc and click OK, which will open Device ManagerRight-click on the name of your computer, and then left-click on scan for hardware changes.Wait for the scan to complete and then check your USB device to see if it works. Disable and Re-enable the USB Controller Right-click Start then left-click RunType devmgmt.msc and click OK, which will open Device ManagerLocate Universal Serial Bus Controllers in the listClick the arrow next to the little USB cable so that it points down instead of to the rightRight-click on the first USB controller in the list and select Uninstall device.Repeat step 5 for each USB controller you find.Turn your computer off and then back on again.Windows will automatically reinstall the USB controllers, so check to see if your device works. 08 of 09 Reset the System Management Controller (Mac) Sjo / Getty Images If you have a Mac, then resetting the system management controller (SMC) may fix your problem. This can be accomplished through the following steps: These instructions do not apply if the Mac has the Apple T2 Security Chip. Resetting the SMC for Macs Shut down the computerPlug in the power adapterPress and hold shift+control+option and then press the power button.Hold all four keys down for 10 seconds.Release the keys and power button all at the same time.Press the power button to turn on your Mac.When the Mac starts back up, the SMC will have reset.Check to see if your USB device works. Resetting the SMC for iMac, Mac Pro, and Mac Mini Shut down the computerUnplug the power adapter.Press the power button and hold it for at least five seconds.Release the power button.Reconnect the power adapter and start the computer.Check to see if your USB device works. 09 of 09 Update Your System Although less likely, there is a chance that updating your system could solve your USB port problems. This process is different depending on whether you’re using Windows or macOS. How to Update Drivers in Windows Update macOS on Mojave and later: Select the Apple icon at the top left, and choose System Preferences.Select Software Update.Choose Update Now if there's an update available. Update macOS on High Sierra and earlier: Open the app store.Click Updates on the toolbar.If any updates are available, click on update or update all.Restart your computer and check to see if your USB device works.