Can't connect both mouse and keyboard in USB ports in back of pc

Page 1 of 2 12 LastLast

  1. Posts : 5
    Windows 7
       #1

    Can't connect both mouse and keyboard in USB ports in back of pc


    It's a pretty specific problem.

    For some time I've had issues with windows forgetting or losing connection to both the mouse and keyboard about a minute after windows started up. It would usually work after restarting, but would show up again about once in every 10 startups.

    Tried to fix it by uninstalling all USB components through the device manager, but now this (other?) issue hits me instead.

    Whenever my mouse and keyboard are both connected in the back of the PC, they screw up each others functionality. I can have the mouse plugged in and working, but when I plug in the keyboard, they both start flashing their lights, and stop working, and vice versa with the keyboard plugged in and then connect the mouse.

    Neither of them seem to mind the USB headset, which is also plugged into the back of the PC. Also it doesn't matter if I use the USB 3 sockets or the regular USB 2 ones - I've tried all possible options: Headset disconnected, mouse and keyboard still hate each other. 1 in USB 3 and the other in USB 2. Both in USB 3, and so on and so fourth.

    I have a temporary workaround in using the USB port in front of the machine for either mouse or keyboard and the other still plugged into the back. That's the only way I can get them to play nicely with each other.

    However, I prefer not to use the front, cus I'm afraid I will damage the port and/or cable, if I hit it with my knee or something.

    I've attached a DxDiag file for spec and system information.


    Hope you can help and thanks so much in advance :)

    /Martin
    Can't connect both mouse and keyboard in USB ports in back of pc Attached Files
      My Computer


  2. Posts : 6,292
    Windows 7 64 Bit Home Premium SP1
       #2

    It sounds like your USB ports are suffering from "power starvation", meaning that the real or resultant voltage exceeds the ports capability.
    "Each USB port is capable of delivering 500mA @ 5Volts max and each port has built in semiconductor fuse that disconnects when external device power drain exceeds rated power output. This fuse will heal itself once the offending device disconnects. This fuse inherits tolerance of 5-10% of 500mA plus or minus. That means it could be disconnecting either on 450mA or 550mA of current drain."
    Now a standard keyboard and mouse would not normally draw anything close to the limit. But some gaming keyboards and mice could draw more than normal.

    More likely, one of those two devices could be defective - a short circuit say - and the result is the system thinks the current is exceeding the limit. Separating the two devices to 2 different USB controllers isolates the problem.

    This is not necessarily the only problem, just the first that comes to mind.

    You could test to prove or eliminate this idea by borrowing a standard keyboard and mouse from another (known working) system. Test to see if your system works with both 'new' devices, then with all the different combinations of 'new' and old devices.

    Hopefully it is that, because otherwise we will have to start suspecting the motherboard.
      My Computer


  3. Posts : 5
    Windows 7
    Thread Starter
       #3

    Thanks for quick response!


    Keyboard: Logitech G510s
    Mouse: Corsair Vengeance M60

    The mouse shouldn't be that power hungry, but the keyboard might be, having a display and light in the keys. The inital issue did, however, start before I purchased that keyboard (last week) and the mouse isn't that old either, so I wouldn't guess the hardware would already be defective... Of course it could be there already from the factory.

    I will test with another keyboard and mouse shortly and post results.

    /Martin
      My Computer


  4. Posts : 1,045
    Win8/8.1,Win7-U64, Vista U64, uncounted Linux distor's
       #4

    I doubt it's a power issue as you have had both devices plugged into USB3 ports that have 900Ma. Both your devices are hard wired so that rules out RF problems. You said you reinstalled all USB. When you did this did you have device manager show all hidden devices? Follow this tutorial and see if that helps. Do a clean usb driver install and then install the mouse and keyboard drivers.

    USB Driver - General Fix for Problems
      My Computer


  5. Posts : 4,466
    Windows 10 Education 64 bit
       #5

    500 MA is a lot of current, 1/2 an Amp. If one of those devices is drawing that much current it has a fault in it that is effectively shorting out the USB bus. LED's draw very little current by the way.
      My Computer


  6. Posts : 25,847
    Windows 10 Pro. 64/ version 1709 Windows 7 Pro/64
       #6

    Your system specs would be helpful.

    By Brink:
    System Info - See Your System Specs

    By Kari:
    Speccy - Publish Snapshot of your System Specs
      My Computer


  7. Posts : 4,466
    Windows 10 Education 64 bit
       #7

    If you open device manager and go to USB Root Hub, you can right click it and go to properties. Under the Power tab it should show how much current is being drawn. It does in Windows 8 anyway.
      My Computer


  8. Posts : 5
    Windows 7
    Thread Starter
       #8

    Layback Bear said:
    Your system specs would be helpful.

    [...]
    I don't understand - do you need further info, than from the attached DxDiag?


    alphanumeric said:
    If you open device manager and go to USB Root Hub, you can right click it and go to properties. Under the Power tab it should show how much current is being drawn. It does in Windows 8 anyway.
    Thanks, tried to check it out. The hubs are no way near the 500ma limit. The front and back both use ~100ma.

    madcratebuilder said:
    I doubt it's a power issue as you have had both devices plugged into USB3 ports that have 900Ma. Both your devices are hard wired so that rules out RF problems. You said you reinstalled all USB. When you did this did you have device manager show all hidden devices? Follow this tutorial and see if that helps. Do a clean usb driver install and then install the mouse and keyboard drivers.

    https://www.sevenforums.com/tutorials...-problems.html
    Holy mother of hidden devices! That was a lot to uninstall one by one I've just finished the tutorial and have 2 questions.
    #1 Would you advise to also uninstall the 'visible' USB devices again in the same go?
    #2 Should I connect the keyboard and mouse before starting the pc again or one by one, once it's fully started up?

    Thanks
      My Computer


  9. Posts : 1,045
    Win8/8.1,Win7-U64, Vista U64, uncounted Linux distor's
       #9

    I would attach the mouse and keyboard then start the computer. The system should find most of the drivers it needs in the system32/driver folder. You should then install the drivers that came with the mouse and keyboard, but it should run with the generic MS drivers.
      My Computer


  10. Posts : 6,292
    Windows 7 64 Bit Home Premium SP1
       #10

    crone87 said:
    Layback Bear said:
    Your system specs would be helpful.

    [...]
    I don't understand - do you need further info, than from the attached DxDiag?
    When you enter your system specs in your forum profile then we can see them simply by clicking the "My System Specs" drop down in your post. It makes things easier for the folks trying to help. Some folks (like me) will not take the time to open an attached file and search for the needed info.


    crone87 said:
    alphanumeric said:
    If you open device manager and go to USB Root Hub, you can right click it and go to properties. Under the Power tab it should show how much current is being drawn. It does in Windows 8 anyway.
    Thanks, tried to check it out. The hubs are no way near the 500ma limit. The front and back both use ~100ma.
    Please note that in my original post I stated that it is highly unlikely that the mouse and keyboard could draw that much power. It is a non-issue. I was trying to say that the symptom is probably caused by something like a power starvation problem, possibly a short circuit or other defect in one of the devices.

    crone87 said:

    Holy mother of hidden devices! That was a lot to uninstall one by one I've just finished the tutorial and have 2 questions.
    #1 Would you advise to also uninstall the 'visible' USB devices again in the same go?
    #2 Should I connect the keyboard and mouse before starting the pc again or one by one, once it's fully started up?

    Thanks
    I suggest running the mouse and keyboard on the generic Windows drivers for a while to test. Then if all is good, install the real drivers - one at a time with time in between - to test for driver conflict.
      My Computer


 
Page 1 of 2 12 LastLast

  Related Discussions
Our Sites
Site Links
About Us
Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

© Designer Media Ltd
All times are GMT -5. The time now is 22:07.
Find Us