My USB port suddenly stopped working.

My USB port suddenly stopped working after inserting another USB device.

My unit has 4 rear USB and 2 front USB port. 2 rear USB port are used for USB mouse and USB keyboard, after inserting another USB speaker in the rear USB port, my mouse and keyboard suddenly stopped working with lights off , after which i transferred my mouse and keyboard in the front USB port and it works fine.

EDIT: i also tried to insert a usb digital camera in the rear port the usb mode will turn on but when i insert my keyboard in the rear port ,the digital camera usb mode will turn off.

any help would be appreciated

Hi Turbonis!


This article from Microsoft support page may help you understand and fix the issue through a few steps like scanning for hardware changes and resetting the USB controller:
https://support.microsoft.com/kb/817900?wa=wsignin1.0


If not, then it could be that the USB ports have just died. For that, you'll need to take your PC to a professional to determine the damage.


Best of luck!


CK_WD

Correct me if I have anything wrong here. So you have two ports on the back side of the computer, which we'll call A and B just to make it easier. If you plug your keyboard and mouse into A and B, they don't work. You plug anything else into either A or B, it works, unless you plug in your mouse or keyboard to A or B at the same time at which point ports A and B stop working. Is that an accurate assessment?

If so, I'd say the most probable explanation is that your keyboard is defective. It probably was slowly damaging the rear ports for a long time until finally they reached a point where it couldn't be sustained anymore. With the keyboard now plugged into the front ports, it'll only be a matter of time before the same thing happens again if my hypothesis is correct. A plausible extrapolation from that hypothesis is that you have a keyboard with a bunch of extra features, all of which have to run off the relatively low amounts of power coming over the USB port. The keyboard wasn't terribly well designed, draws too much power, which slowly damages the USB port over time until it reaches a point where it can't support that extra power and trips some kind of safety cutout circuit explaining why the mouse or camera also dies when the keyboard is plugged in. If you can find an old USB keyboard, ideally just a bog standard 103-key keyboard, no extra functions of any kind, try plugging that into the rear port and see what happens.

USB2 ports have power limit of 0.5 A (500mA) which is 2.5W so overloading them with anything that's over it may cause malfunction. On some computers they are in pairs on same controller so overloading one connector may stop other one from working.

@asvent your assessement is almost correct. I got 4 usb ports at the back. I have been using this keyboard for almost 5 years.
btw i've recently changed my motherboard a month ago.

@CKWD i already tried methods 1,2 and 3. nothing works.

Aging and dying, it catches up even with electronics. You haven't given any system specs or how old your system is.

In that case it could be absolutely what @CountMike suggested: perhaps one of your peripherals is faulty and crashing other USB devices. You could test this theory by inserting another (for surely) working keyboard and mouse along with other USB devices. If it works without a problem either the mouse or keyboard is damaged and needs to be replaced.


Best of luck!


CK_WD

You may have to completely power down to reset the port(s) if they have tripped off do to an overcurrent event. Power down the PC. Then unplug the power supply from the wall outlet. Now press the case power button for about 5 seconds. That will drain any residual power in the power supply. Now plug it back in and boot up.

turbonis said:

@asvent your assessement is almost correct. I got 4 usb ports at the back. I have been using this keyboard for almost 5 years.
btw i've recently changed my motherboard a month ago.

@CKWD i already tried methods 1,2 and 3. nothing works.

Click to expand...

Do you have a spare keyboard around you can use to test?

Also, from an engineering standpoint, USB ports are absolutely horrible. I can only assume that they are extremely cheap and that's why they went with such a horrendous design. They basically glue flat metal pins to a bit of plastic and then when you plug a device in the pins slide over top the pins in the other port to create a connection. Every time they make a new version of USB they compound the issue to maintain backwards compatibility and just recess the pins further back which causes intermittent connectivity problems over time. They also never solved the issue of what happens if the glue starts to break down and one or more pins isn't precisely in alignment? Bent pins is the answer. I one time saw a Mac Mini where someone had REALLY gone at the thing trying to plug something in because the pins inside the port on the unit were practically folded in half.

So at some point you may have plugged in your USB cable at an angle and caused problems, it could just be that there's some corrosion forming on the pins causing a short, maybe there's something wrong with the electronics on the keyboard sending a feedback loop to the port. One of the quickest and easiest ways to test is to get a spare keyboard. Never a bad idea to have a spare keyboard anyway. I like to keep one of those rubber rollable keyboards around in the event I ever find myself in need of a keyboard on short notice... Like it's the middle of the night, my keyboard craps out and I absolutely have to get something done by tomorrow. The rubber ones can be rolled up and take up less room even if they suck in practically every other way.