1 usb port works. Repair of computers and laptops; firmware for tablets, phones and navigators in Adler, Krasnaya Polyana, Khosta, Kudepsta, Vesely and Moldovka. Troubleshooting steps
The presence of USB connectors allows you to connect a wide variety of external devices to your laptop, from flash drives to printers and scanners. This connection method is very convenient, so there are USB connectors on almost all modern computers, including laptops and netbooks. Unfortunately, sometimes they can fail - the next time you connect an external device, the user may find that this cannot be done.
Why did the USB ports on my laptop stop working?
This question is asked by every user who encounters this malfunction. All reasons can be divided into two types - software and hardware. In the first case we are talking about failures software, and the reasons for these failures may also be different. For example, external ports may be disabled by viruses. Damage or absence of the corresponding driver files can also lead to their inoperability.
There is a very simple way to check the health of your computer hardware: if you are running Windows, boot your computer from a boot disk or flash drive with the operating system Ubuntu system(demo mode, no installation). It can be downloaded completely free of charge, and the OS can easily “pick up” the vast majority of modern computer equipment. If the ports work under Ubuntu, then Windows is to blame. Didn't work - the reason is hardware in nature.
Why don't USB ports work?on the computer, I connect any device, but it is not detected. I always use the USB port located on the front panel system unit, but I also tried using USB ports located directly on the motherboard, the same result. Would you recommend reinstalling the operating system? ?
Sergey
One USB port on my laptop does not work, all the others work, I will say frankly that I connected a faulty flash drive to it, the laptop is still under warranty, do you think the USB controller failed due to a burnt flash drive or a bug in the operating system. How can you accurately determine? I don't want to reinstall.
Basil
Why don't USB ports work?
Malfunctions in both cases can be very different, so let's first look at the first case, when all USB ports on a computer or laptop do not work, and then the second. Continued in the article .
First of all,Why don't USB ports work?, so it’s probably the USB controller on the motherboard that is disabled, it may well turn itself off, you can turn it on by going into the BIOS. How to get into it? In the initial phase of booting the computer, we often press F2 or Delete as it is exactly written in the instructions for your motherboard or look at our website for many articles about this.
- Maybe you have one faulty USB device in the system unit and the problem is due to it, turn off the computer, disconnect everything: USB keyboard, mouse, etc., then turn on and connect one known-good flash drive, if it works, you need to look for the problem in peripheral devices.
- Likewise, if USB ports don't work, you need to go to Device Manager and look for the presence of the USB Serial Bus Controllers item, if any device is marked with a yellow exclamation mark, it means it is faulty, double-click on it and the device window will open, where information about the fault can be displayed.
- You can try to remove all USB controllers in the device manager and reboot, the operating system will install them again, after which they can work
- Maybe you had system restore enabled, you should try using control points will roll back.
- Sometimes you can overload a USB hub and it will refuse to work; this can be cured by simply rebooting the computer.
- Most USB hubs have power management and the operating system can turn off the device to save power. Let's prevent Windows from managing the power supply of the USB controller; in Device Manager, expand the Universal Serial Bus Controllers branch, then USB Root Hub, double-click the left mouse and select Power Management. Reset the checkbox Allow this device to turn off to save power and click OK, you need to do this for each USB Root Hub.
- Install a new driver on the motherboard chipset; our article will help you do this.
- One of our users had a problem with USB ports resolved replacing the CMOS coin cell battery on the motherboard.
- , often helps with such problems.
- If you have constant problems with USB ports, install a PCI-USB controller.
- If you bought external USB hub with its own power supply and the devices connected to it are not seen by the operating system, you need to check this hub on another computer, if everything is fine there, then the problem may primarily be in your faulty power supply (only replacing it with a more powerful one will help), but first of all you need try reinstalling the operating system.
In the BIOS we need the Integrated Peripherals item, this is in the Award BIOS, and in the Ami BIOS the Advanced item, find them and press Enter, then go to USB Configuration, if our USB Controller or USB Controller 2.0 is turned on, it is in the Enabled position, otherwise it is turned off, that is, it is in the Disabled position, then you need to turn it on, save our changes and reboot, the problem should go away.
Unfortunately, sometimes you have to reinstall Windows to find out exactly what is causing the problems, whether it is the hardware or the operating system.
Or you don’t have to reinstall, just boot from any Live CD and check whether your USB ports will work; if so, then you need to look for problems in Windows. You can try reinstalling the drivers for the motherboard chipset. If USB ports do not work in the Live CD disk operating system, then the problem is in the hardware and read on.
If, when connecting a device via USB, it does not initialize, it is not detected operating system and does not display any messages at all, then perhaps the reason is disabled controller responsible for this port.
The first thing to do is look port status in Device Manager. To launch it, enter in the window Execute(Win+R) command " devmgmt.msc».
Open section USB controllers and look state USB hub or USB root hub. 
The picture shows one of them disabled. Enable it using the right button – Engage.
You can also go to the section properties– tab Power management, uncheck the permission to turn off devices to save power. 
In the same properties you can check relevance installed drivers, update them if necessary. 
If the controller is marked yellow exclamation mark then try reinstall its driver, or remove all controllers and run reboot system, after which they should automatically install and work properly. 
All ports do not work
If all ports do not work at once - reboot computer and go to BIOS(key F2 or del at startup). Depending on the BIOS type and version, the settings may vary, You should find the parameters " USB Function" And " USB 2.0 Controller", they should be in the " Enabled" Most often they are located in the “ Onboard Devices Configuration» 
Only the front connectors do not work
If we are talking about a PC, then we should distinguish front And rear connectors. The rear ones are located directly on the motherboard, the front ones are connected to it using a special plume. Therefore, when the front USB stopped working, first of all check operation of the device when connected to the rear. 
If it is correct, then you will have to remove the cover system unit (with the computer power off), and then check correct connection front connector cable to the system board.
Correct pinout connections can be found in the description of your motherboard, but usually how to connect is clear signatures on the motherboard.
Other reasons and solutions
If you are using extension or hub Check the operation of these devices when connected to other ports or on another computer.
If we are talking about broken connector USB 3.0, check whether its special cable is connected to the appropriate connector on the motherboard.
Check drivers the devices themselves, connected through the ports, the reason may be in these devices, and not in the connectors.
If none of the methods worked, then this particular port or controller probably has mechanical damage that can be repaired at a service center.
It is difficult to imagine a modern computer without such a familiar USB port. Thanks to it, a mouse, keyboard, printer, and flash memory cards are so conveniently connected to a PC.
It happens that USB connectors suddenly stop working, usually this happens at the most inopportune moment. But don’t rush to immediately run to the service center and pay a lot of money. Perhaps the problem is at the system level and you can solve it yourself.
Now we will look at several of the most likely causes of the malfunction and ways to solve them.
Sometimes it happens that after purchasing new computer straight from the store, you come home, are happy with your purchase and “use it with all your might,” but when you connect a flash memory card or any other USB device, you discover that the computer does not see them. This is a fairly common and widespread problem; you just need to connect the USB ports at the system level, through the BIOS. It is not difficult.
We go into the BIOS, look for the section “ Integrated Peripherals" or " Advanced" - depending on the BIOS version. We go and look for the “section”, make sure that the first two paragraphs have the value “Enabled”. This shows that the inputs are connected. If not, then change the value. After the corrections, exit the BIOS, saving the settings, reboot the computer and check its functionality.
It is also worth checking whether the ports are connected to the motherboard, this happens.
If the inputs at the front of the computer do not work, you should try connecting the device to the rear inputs, which are directly connected to the motherboard. If this helps, we can conclude that the front USB inputs are not working due to a lack of power, which is transmitted through the cable from the motherboard. In this case, I recommend using such ports only for flash drives, since they do not need large quantities nutrition. And it is better to connect printers and other devices to the built-in outputs.
If it doesn't help, move on.
The operation of any part of the computer is regulated by drivers, and USB is no exception.
Reboot PC
Endless loading of a flash drive, a constantly creeping message “Device not recognized” or just no reaction to the connected device? Often, simply restarting your computer is enough to solve these problems. If any errors or damage to the drivers occur, then after a reboot in automatic mode, the system will restore them to their original form.
Device manager and updating hardware configuration.
It happens that you cannot restart your computer right now due to some important process. You can restore drivers through Device Manager. You can call it in two ways:
1. Right-click on the “My Computer” shortcut and select “Manage” from the pop-up menu;
2. Select Run from the Start menu. In the field, enter the command devmgmt.msc.
So, the device manager menu opened for us. We look for the “USB Controllers” item, right-click the “Update Hardware Configuration” command. After this everything should work. 
Removing the “USB Controller”
In our next method We continue to work with the same menu. If simply updating the drivers does not help, we will try to remove and then reinstall the same drivers again.
Important! If your mouse is connected to the computer via a USB connection, then when you remove the drivers, it will stop working after removing the corresponding driver. But don't panic! After a reboot, everything will return to normal.
Open the already familiar “Device Manager” menu. In the “USB Controllers” section, select each device in turn, press the right mouse button and click “delete”. 
Here your task is to leave the mouse at the end and remove the driver for its port last. After this, restart the computer. Standard drivers are included in the system. Therefore, after a reboot they will reinstall themselves, this should solve the problem.
You can also manually reinstall the drivers. But to do this, you first need to find out which driver needs to be installed. This can be done using software that can show you the necessary information, such as EVEREST. We look at the port model, download and install the appropriate software.
Port congestion
Each USB input is designed for a specific current. If your computer is under the table and for convenience you have brought the ports to the table via a USB hub, this may cause inoperability. The fact is that the motherboard is programmed to allocate a certain amount of current to power the USB inputs. But if you made six inputs from one and inserted a device into each of them, then the motherboard is not able to supply the required amount of current to ensure the operation of all connected devices. The protection is triggered and the power is cut off.
First, try turning off all unnecessary devices. If this doesn't help, unplug the hub and connect the device directly without it. Before doing this, it is advisable to reboot the system.
If all of the above methods did not help solve the problem, you should try reinstalling the operating system. It happens that some kind of update comes out to the system, even a small one, and it begins to conflict with already installed drivers.
USB and Windows 10
After upgrading your PC to Windows 10, it’s not uncommon to see reports on various forums about problems with USB inputs (and not only, to be honest). This is justified by the “dampness” of the system. The further away from the release, the more fixes were released, including those to eliminate these problems. Therefore, I recommend that if such a problem occurs, first check the system for updates. If it doesn’t help, write to the manufacturer and wait for a solution to the problem.
If all of the above methods did not help, most likely there is a breakdown in the technical part of the computer. The most harmless option may be that some foreign object gets into the port, which prevents the device from connecting properly.
More serious may be damage to the controller itself of one of the ports or, worst of all, a breakdown of the north bridge, which is responsible for the operation of the USB inputs. If replacing one controller is not expensive, although for laptops this is also expensive, then replacing the south bridge will cost you a pretty penny. Repairing it is almost impossible.
The only way out in such a situation is to contact a service center.
Sometimes it happens that the operation of all ports is blocked by one device connected to the computer. It is necessary to disconnect all devices and try to connect one at a time, checking their operation each time. It often happens that due to a faulty plug, for example, a keyboard or mouse, it shorts or shorts all the ports.
Although this happens quite rarely now, it happens that the computer has a low-power power supply, 300V, for example, and the problem may be hidden there. It’s worth trying to replace it with a more powerful one, at least 450-500V. In any case, installing a better power supply will not interfere with the operation of the computer.
In conclusion, it is worth noting that problems can occur both in the system and in the technical part. If it was not possible to fix the problem, from a system point of view, then without the proper knowledge, you should not go under the cover of your computer or laptop and try to solder the sockets; it is better to leave this to trained people in service centers.
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USB technology is one of the most important of the many technologies that have made a huge impact in the computer world. USB (Universal Serial Bus- “universal serial bus”) - a serial data transfer interface for low- and medium-speed computer peripheral devices
This technology has made it truly easy and convenient work with printers, scanners and external storage devices (external hard drives, USB flash drives). All actions with installing USB devices came down to a simple principle: “ Plug and play" Devices have become truly mobile precisely because of USB technology. Today, not only desktop PCs and laptops are equipped with USB ports, but also gaming devices, smartphones, cameras, navigators and many other devices.
Ports USB version 2.0 provide data transfer at speeds up to 480 Mbit/s, and the version USB 3.0 raises maximum speed transfers up to 5.0 Gbit/s. The USB symbol is a kind of trident, drawn both on USB devices and on computer connectors.
USB technology has already been studied quite seriously and has undergone many improvements, so USB ports, when used correctly, rarely cause any problems, and troubleshooting problems associated with them does not cause much trouble. This article will outline the basic principles of troubleshooting USB ports.
But before we begin, it’s worth describing basic recommendations when working with USB ports and devices, connected to them:
- never connect devices with visible mechanical damage to USB connectors, as well as devices with external damage to the case or with a clear burning smell.
If the USB ports on the motherboard are mechanically damaged, it is better to disconnect them from the motherboard (the connectors on the front of the case) or seal them with colored tape to prevent their use. If necessary, it is better to replace such ports in a workshop with new ones.
Try not to overload USB ports. Their current strength is strictly limited: 500 mA for USB 2.0 and 900 mA for version 3.0. Do not try to increase the number of USB ports using various USB multipliers. Modern motherboards already have up to 10 ports, which is quite enough for home use. It is always safer to buy an additional PCI or PCIe USB controller than to work through a USB “tee”.
If the USB ports on a laptop stop working, then working on it becomes very difficult - you cannot connect a printer, a scanner, or a flash drive. And unlike a desktop computer, installing an additional USB controller is very expensive.
In many cases, when the error message " USB device not recognized "The problem may be in the USB port. This problem is usually solved quite easily, since it occurs mainly at the software level.
What to do if the USB ports do not work?
Any hardware device interacts with the installed operating system through special program - driver. Many problems with devices are solved with the help of drivers. The same is the case with non-functional USB ports. Below are several methods that will help you troubleshoot USB ports at the software level.
If the USB ports suddenly stop working, and USB devices are not detected, then the most in a simple way The solution to this sudden problem will be to restart your computer. Just restart your computer. If there were no problems loading the drivers, this problem will be resolved after a reboot.
Update hardware configuration in Device Manager
If restarting the computer is not desirable at the moment (for example, because some important operation is being performed), then you can “reload” the drivers without rebooting the entire computer via device Manager. To launch it on the shortcut " My computer» right-click and select the menu item « Management e". Or in the menu " Start» find the program « Execute"and after launching it, enter the command devmgmt.msc.
In the window that opens, left-click once on the list of devices and then click the tab " in the main menu Action", then point to " Update hardware configuration" See if the section “ USB controllers" If yes, then your problem is solved, the USB ports should work.
Another way to get USB ports to work is to unplug and then reinstall the USB controller. To do this you need to run again device Manager. In the list of equipment that you will see in the window that opens, find the USB controllers section. On each of the devices in this section, right-click and delete them all. Once you remove all controllers, simply restart your computer. The controllers will be reinstalled and the USB ports will become available again. This may solve your problem.
Updating USB controller drivers
Another reason that USB ports do not work is damage to the USB controller drivers. The only way out is to find the correct drivers and reinstall them. To download the appropriate driver, you need to find out the manufacturer of the USB device port (via it). Installing the correct driver should solve this problem in an instant.
Disabling other USB devices
Sometimes USB ports do not work due to overload when too many USB devices are connected. USB hubs sometimes do not provide enough power to the devices connected to it. The connected device can consume all the permitted power of the computer's USB controllers. If the equipment is connected to a USB hub, then simply connect the device directly to a USB port on your computer.
You can also leave the device connected to the USB hub, but first disconnect other devices in the hub. For the future, purchase a USB hub with its own power supply that will provide sufficient power to all devices connected to it.
If none of the above methods worked, then it is likely that the USB ports were physically damaged. Or the USB controller, in particular the south bridge of the motherboard, is damaged. In this case, the best thing you can do is replace or repair the USB port controller at a service center.
