How to "restart/repair" an USB port?

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My laptop has two USB ports, but one is broken, so I use a USB hub in the other good USB port. In that USB hub, I use a mouse and keyboard. Suddenly, that USB port doesn't detect the mouse and the keyboard (even with the light of the hub is on), and the only solution that I found is restarting the laptop. But just some minutes and the keyboard and mouse goes undetected again...

Is there some method, software, etc. to "restart/repair" the USB port without restarting the PC?

Click Ok

Posted 2009-12-17T21:45:35.870

Reputation: 3 436

Answers

18

None of the answers quite answer the title question.

How to “restart/repair” a USB port?

There are three ways to "restart" a particular USB port:

  1. Reboot the computer. Or ...
  2. Unplug, then re-plug, the physical device connected to the port. Or ...
  3. Disable, then re-enable, the USB Root Hub device that the port is attached to.

In Windows you'd do (3) through the Device Manager or via the devcon.exe utility.

The reason these are the only methods is due to the USB handshaking protocol, which is initiated by the USB device when it's plugged in, not by the controller. This causes problems like being unable to remount a USB flash drive after you've Safely Removed it. But cycling the USB Root Hub device causes all the devices attached to that hub to reinitialize themselves. (The unfortunate side effect is that it causes all devices attached to that hub to reinitialize themselves, which could be problematic if you have other devices on that hub which are in use.)

quack quixote

Posted 2009-12-17T21:45:35.870

Reputation: 37 382

is it possible to disable a hub that is running your keyboard / mouse (internal or external) thus making it impossible to restart the hub again? I guess not otherwise somebody would have said so by now....... or maybe that can't with no keyboard?... – Simon – 2016-09-20T00:08:26.680

Unplug then replug is the best solution, if possible. Restarting the computer as well as disabling then enabling the USB device may not fix all the problems, as the device stays powered the whole time. – user276648 – 2018-10-15T02:24:31.693

This is THE answer – pratnala – 2013-03-12T09:43:31.217

4

I had issues with Windows 7 dropping the USB mouse driver and reinstalling the mouse driver (most of the time) which was annoying as hell.

I tried all kinds of things to fix the problem, driver updates, clean boots, tech support phone calls, Internet software voodoo, but in the end I only had to reset my USB ports.

I did this by turning the computer off, unplugging all USB devices, removing the laptop battery and AC power supply, and finally holding down the power button for 30 seconds.

This fixed a problem that I must have spent at least 20 hours trying to fix; give it a try.

Signats

Posted 2009-12-17T21:45:35.870

Reputation: 41

3

If you have no power supply added to the USB hub, check if that helps. Maybe the laptop doesn't have not enough power on the USB; some older laptops didn't have not the full 500 mA.

Thomas

Posted 2009-12-17T21:45:35.870

Reputation: 272

It is not a lack of voltage, but instead one of current. Think of it like a pipe -- the Voltage is the size of the pipe and Current is how much water you have. All USB port devices connect to a 5v pipe but only has 500ma of water, if all of the devices don't get enough water(electricity) they don't work. Each device uses a certain amount of the 500ma available if you over load the circuit then all of the devices can behave wonkey. the hub itself also uses part of that 500ma so powering it powers the devices you attach to it. – Rowan Hawkins – 2019-11-18T16:58:47.603

1Interesting! How I can check that voltage? – Click Ok – 2009-12-18T00:09:02.680

2Powering a mouse and a keyboard via the USB port should not be a problem. I really wouldn't worry about that. – Paul Lammertsma – 2009-12-18T10:56:45.760

Some computers show the voltage in their driver settings. Regarding the power consumption - or the problem - try finding the combination that brings trouble by using only one of the components, e.g. only mouse without the hub and the keyboard and if that works use only the keyboard and so on. Alternatively you can check if you have a power supply that fits to the hub, e.g. on my hub I the disk did not work and I found a 5V power supply that had the same +- combination and plug and now it works. Again: My old Dell Laptop produced only 300-400 mA. – Thomas – 2009-12-18T11:22:33.243

3

You should look at NIRSOFT's USB Device view (http://www.nirsoft.net/utils/usb_devices_view.html). I have used this to fix a system that had a disconnected U3 USB drive still mounted preventing anything else in the port being recognized.

jtreser

Posted 2009-12-17T21:45:35.870

Reputation: 940

Nirsoft is good at removing the drivers for devices that are not attached as well. This lets you reset and then reattach the device. – Rowan Hawkins – 2019-11-18T17:02:27.220

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Can you check your event viewer for any obvious errors in the application or system logs?

I don't know what the problem is at this point, but you should inspect the drivers installed. Are they Microsoft default input drivers or custom drivers? You might need to reinstall the drivers. It could be possible that the instance of the drivers is failing.

Also try inspecting the drivers after plugging in the device. You might see a resource conflict or some other warning in Device Manager.

Since the problem is occurring for two different devices, I think it's less likely a hardware failure on the mouse or keyboard.

The failure is definitely on your laptop.

Andrew Keith

Posted 2009-12-17T21:45:35.870

Reputation: 356

1

Go to Task Manager, and you will find a warning label on the device you are having problems with. Just unplug your device, and put it into another computer or laptop. If it works on other computers it's definitely a problem with your USB port. Try replacing it, contact experts, and change it. Try it, and it will work definitely. If you find problems please change your motherboard. Please don't buy a new one because the device has no problem.

And if any of that didn't work, try USBDeview. It lets you view all installed/connected USB devices on your system. You can read more about it on its download page.

ILIkeTOHELP

Posted 2009-12-17T21:45:35.870

Reputation: 11

0

Here's how to reset your USB after a power surge or other anomaly that causes devices to not register with the system:

  • Start
  • Control Panel
  • Device Manager
  • Right Click on Universal Serial Bus Controllers
  • Click Scan For Hardware Changes.

user522382

Posted 2009-12-17T21:45:35.870

Reputation: 1

0

Is there some method, software, etc. to "restart/repair" the USB port without restarting the PC?

*Note I take no responsibility for ANY damage this causes to you or your computer following these directions. The responsibility and usage of these methods is solely on you.

Method I:

  1. Open System Control Panel. (windows key + pause break)
  2. Click Device Manager.
  3. Expand Universal Serial Bus Controllers.

  4. On Every Device Starting From The Top Called "USB Root Hub"

    A. Right-Click

    B. Select Properties

    C. Click Advanced Tab

    D. Click Reset Hub

Method II:

  1. Download DevCon - https://docs.microsoft.com/en-us//windows-hardware/drivers/devtest/devcon
  2. Open cmd.exe as administrator. https://technet.microsoft.com/en-us/library/cc947813(v=ws.10).aspx
  3. Browse to the devcon.exe location in command prompt. Example: cd Program Files (x86)\Windows Kits\10\Tools\x64 (varies on windows kit you installed for path as well as x86 vs x64 bit windows machines)
  4. Type devcon.exe restart (Asterisk)root_hub(Asterisk)

-Remove parenthesis and use actual symbol for Asterisk. Sorry Forum removes them in the post so I can't type them literally.

Some USB ports may report restart required. These hubs may unfortunately not be restarted without a reboot.

Up-vote if it helps so more will see. Came here myself via google search and was able to accomplish what I needed in both methods I listed above.

Enjoy.

TeamJica

Posted 2009-12-17T21:45:35.870

Reputation: 1

0

this worked better for me 1] Enable, Disable USB Drives & Mass Storage Devices using Registry

Go to Start > Run, type “regedit” and press enter to open the registry editor Navigate to the following key

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR

In the right pane, select Start and change the value to 3. (The value 4 will disable USB Storage). Click OK. This will re-enable USB Ports and allow you to use USB or Pen drives.

David

Posted 2009-12-17T21:45:35.870

Reputation: 1

0

  1. Go to "Device Manager" (open Control Panel in "Start Window")
  2. Go To "Universal Serial Port controllers"
  3. Look for "Exclamation Point" on one or more of the controllers
  4. (Right click mouse) Disable, then (right click mouse) Enable
  5. Done!!

user330404

Posted 2009-12-17T21:45:35.870

Reputation: 1

Basically the same answer as quack quixote already gave

– nixda – 2014-06-08T08:34:26.633

Asked: 2009-12-17T21:45:35.870

Viewed: 188 402 times

Active: 2018-04-26T10:42:45.503