RandyMeeks
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Q: Mouse and keyboard don't work at startup or after being unplugged

Hi, I've an iMac 21.5" since 2013, and since the beginning I have a recurring problem.

 

Sometimes mouse and keyboard don't work at startup. They are not recognized, and they are not even powered on (no light under the mouse, and no green light on the caps key).

 

The same problem occurs when I unplug the keyboard while the iMac is on : the keyboard and mouse won't work when I plug them back, and I have no option but to force shutdown.

 

Usually the problem disappears after leaving the computer off during a certain period of time. Sometimes it also helps to unplug it for 15 minutes.

 

Do you know what's the problem, and how to solve it ?

iMac (21.5-inch, Late 2012), OS X Mavericks (10.9.2)

Posted on Dec 24, 2014 9:00 AM

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RandyMeeks

Q: Mouse and keyboard don't work at startup or after being unplugged

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  • by rkaufmann87,

    rkaufmann87 rkaufmann87 Dec 24, 2014 9:32 AM in response to RandyMeeks
    Level 9 (58,956 points)
    Photos for Mac
    Dec 24, 2014 9:32 AM in response to RandyMeeks

    Please use Troubleshooting wireless mouse and keyboard issues - Apple Support to troubleshoot the issue.

  • by RandyMeeks,

    RandyMeeks RandyMeeks Dec 24, 2014 1:46 PM in response to rkaufmann87
    Level 1 (0 points)
    Dec 24, 2014 1:46 PM in response to rkaufmann87

    Thanks for your answer, but I forgot to write that my keyboard and mouse are USB. And your link is only about wireless devices.

  • by K Shaffer,Helpful

    K Shaffer K Shaffer Dec 25, 2014 3:02 AM in response to RandyMeeks
    Level 6 (14,582 points)
    Desktops
    Dec 25, 2014 3:02 AM in response to RandyMeeks

    Well, the 'unplugged' reference was noted earlier and I wasn't sure if you'd get a

    better response than a standard suggestion to try the other ideas in this link first

    •Intel-based Macs: Resetting the System Management Controller (SMC) - Apple Support

    before actually performing the SMC, that is a dragnet kind of catch-all, sometimes.

     

    All of my keyboard & mouse units are USB and I've gone as far as supplying the

    mouse and other peripherals with a powered USB hub; so power from the Mac

    isn't spread too thin. The keyboard is one of the only items that should be attached

    to the USB port; as it has to work on startup pre-boot keyboard shortcuts... Such

    as SafeBoot, PRAM reset, and others where you need a live keyboard and BT

    may not be up to the task of being ready. Three going on four of my Macs have

    bluetooth capabilities for those items; but I can't justify the continual upkeep cost.

     

    Spare USB keyboards and a few extra mouse are handy as troubleshooting tools, too.

     

    There are some USB keyboard references among search results in this linked page:

    https://www.google.com/?gws_rd=ssl#q=Apple+USB+keyboard+troubleshooting

     

    Perhaps the SMC pre-reset suggestions may help resolve the issue, if not, try reset.

    Good luck & happy computing!

     

    edited

  • by rkaufmann87,Helpful

    rkaufmann87 rkaufmann87 Dec 25, 2014 7:42 AM in response to RandyMeeks
    Level 9 (58,956 points)
    Photos for Mac
    Dec 25, 2014 7:42 AM in response to RandyMeeks

    RandyMeeks wrote:

     

    Thanks for your answer, but I forgot to write that my keyboard and mouse are USB. And your link is only about wireless devices.

    Thanks, that is important information! Where I would start is to make sue both the mouse and keyboard and plugged in directly to the iMac. In other words if you are using a USB hub then please eliminate that from the equation. Next do 2-3 SMC resets and a PRAM reset.  Instructions are in Intel iMac SMC and PRAM resets

  • by RandyMeeks,

    RandyMeeks RandyMeeks Dec 25, 2014 1:55 PM in response to K Shaffer
    Level 1 (0 points)
    Dec 25, 2014 1:55 PM in response to K Shaffer

    Thank you to both of you for your answers.

    I don't use USB hub.

     

    And I know the SMC reset thing. Yes, indeed, it works... until next time the problem occurs.

    So I'm looking for a definitive way to solve the problem, because I'm tired to force shutdown and I suppose it's not a good practice on the long term for the well-being of my iMac .

  • by rkaufmann87,

    rkaufmann87 rkaufmann87 Dec 25, 2014 2:08 PM in response to RandyMeeks
    Level 9 (58,956 points)
    Photos for Mac
    Dec 25, 2014 2:08 PM in response to RandyMeeks

    Your welcome.

  • by K Shaffer,

    K Shaffer K Shaffer Dec 25, 2014 2:35 PM in response to RandyMeeks
    Level 6 (14,582 points)
    Desktops
    Dec 25, 2014 2:35 PM in response to RandyMeeks

    Not sure if a trip to an authorized service provider, or to try & schedule

    a genius appointment with the staff at an Apple Store; but the issue

    may invite a need to have diagnostic testing at a professional level.

     

    Be sure you backup your system and your work files, in case there is

    a hardware issue that could cause their loss; if not already done.

    Not sure if the PRAM or NVRAM reset (slightly different than SMC)

    could be of any help, because the system itself may need to be

    re-installed, as part of greater or more extensive troubleshooting.

     

    •How to Reset NVRAM (PRAM) on your Mac - Apple Support

     

    Other power related problems can be sometimes resolved by use

    of the NVRAM reset. With either of the already suggested resets,

    make sure to try it more than once. Also, you could safeboot and

    see if repairing disk permissions could help. Little things may.

     

    Hopefully you can resolve this issue.

    Good luck & happy computing!