There are a lot of peripherals you can hook up to your Mac, and any one of them could stop working. We’re talking about mice, keyboards, printers, scanners, tablets, iPhones, iPads, iPods, hard drives, etc. While you can find specific troubleshooting guides for some of these peripherals on MacGuruLounge, I wanted to offer you some troubleshooting tips that you could use on any peripheral. This guide is designed to isolate where the problem occurs: with the peripheral itself, its cable, your Mac’s hardware, or your Mac’s software. Follow this guide in order for best results:
- For troubleshooting USB devices (including wireless devices that use USB dongles), only plug them into your computer, not your keyboard. This ensures they receive the necessary power current.
- Verify that your USB/FireWire/Thunderbolt cable is securely attached to the computer and peripheral.
- Unplug the cable from the computer and try reconnecting it to a different USB/FireWire/Thunderbolt port on the computer (if this is possible).
- Disconnect the cable from both the computer and the peripheral. If you must plug your peripheral into the wall for electricity, unplug it from the wall, wait 5-10 seconds, then plug it back in. Now reconnect the cable between the computer and the peripheral.
- If you have an alternate cable you can use to connect the computer and device, give it a try, too.
- Restart your computer and try the previous steps again before moving on.
- Optional step: Before moving on to software, you can try plugging the peripheral into a second computer (if you have one). If it works, you can reject the conclusion that the peripheral or cable is faulty. If your device requires a driver, make sure you install it on the second computer before plugging the device in.
- Download the latest driver from your peripheral manufacturer’s website. Uninstall the current driver (if there is one) and then install the latest driver. You may need to restart your computer. Disconnect and reconnect your peripheral’s cable from the computer. This tests whether the problem is an outdated software driver.
- Create a new user account. Log out of your user account, log into the new one, and then disconnect and reconnect the peripheral. If your device works here, there is a problem specifically with your user account (this is not very common).
- Finally, if all of this fails, you can call the manufacturer of the peripheral to see if they can help troubleshoot your problem. Likewise, you could take your computer and peripheral to a local Apple Store for assistance at the Genius Bar.
If you want to eliminate your USB/FireWire/Thunderbolt ports as a possible hardware problem, try plugging a peripheral that is known to work into each port and verify that the same device still works in each port. For example, if you cannot get your printer to work, but your mouse functions, plug your mouse into each USB port and verify that it works. If it does, you know your USB ports are fine. If it does not work in one of the ports, you should consider that port faulty, since you know the mouse works when connected to the other ports. While not guaranteed, faulty ports likely require a hardware repair.
Did this guide help you with your problem? How else have you troubleshooted peripherals and your Mac? Let others know in the comments.