USB connected Apple Mouse keeps disconnecting intermittendly

Discussion in 'iMac' started by spirelli, May 29, 2019.

  1. spirelli macrumors newbie

    Feb 24, 2014
    I've got an Apple Mouse connected via cable directly to one of my iMac's USB sockets. It seems to be disconnecting and reconnecting intermittently, with it repeatedly becoming unresponsive for short periods of time. Clicking and scrolling doesn't work.

    I can see the scroll bars of apps diappearing and reappearing which happens in sync with the mouse becoming unresponsive. You can simulate this by unplugging and plugging the mouse. (Many MacOS applications (Finder, Mail, activity monitor, terminal, etc) show permanent scroll bars when a mouse is present and auto-hide scroll bars when only a touch pad is used, for example.

    At the same time there is no issue with the keyboard it works even when the mouse doesn't. The same happens when the mouse is plugged into the keyboard's USB socket.

    The periods of unresponsiveness vary: it seems to be less after starting the computer and gradually becoming more frequent. Unplugging the mouse and replugging it into a different USD socket also makes a difference: most of the time the issue becomes less frequent before it happens more often (which is every few seconds).

    The issue arose after I updated the OS to 10.14.5 (not immediately but a few hours later on the same date), and I'm not sure whether it's connected in any way.

    Here is what I've tried to resolve the situation:

    • Use a second Administrator user

    • Run iMac in Safemode

    • Disconnect all peripherals

    • Disconnect from the Internet

    • Reset MVRAM

    • Reset SMC

    • Reapply MacOS update 10.14.5

    • Use a second Apple Mouse

    None of the above have changed the situation. Apple Support Chat don't seem to have any further ideas.

    I would be grateful for any tips and help here in the forum, because at times the computer is almost unusable.

    Also, any ideas whether this is a software problem or a hardware problem, e.g. faulty component to do with USB?

    Attached are some screen shots of the USB section of the System report and from the Activity monitor (if that helps).

    Thank you for any answers!

    Attached Files:

  2. mikehalloran macrumors 65816

    Oct 14, 2018
    The Sillie Con Valley
    This is an old issue. Turn off Bluetooth and see if that fixes it.

    If it does, something, somewhere has paired with your Mac and is taking over. The fix is easy—leave BT off or go in and unpair everything. Now pair only the devices you need to see your Mac.

    When it happened to my wife, it was only when my daughter was home from college. Somehow, her BT mouse had paired with her iMac.
  3. SecuritySteve, May 29, 2019
    Last edited: May 29, 2019

    SecuritySteve macrumors 6502a


    Jul 6, 2017
    Does it happen with a non-Apple mouse, and does it happen if you change which USB port you plug it into? Does the problem persist if you revert back to 10.14.4?

    I'm a little worried that Apple might not be supporting / QA testing the old Apple Mouse. The design itself dates back to 2005, and was discontinued almost two years ago.
  4. chrfr macrumors 604

    Jul 11, 2009
    The old Apple mice tended to have cable failures right at the base of the mouse itself. This may be your problem, depending on the age of the mouse.
  5. spirelli thread starter macrumors newbie

    Feb 24, 2014
    Thank you for your feedback.

    1) Haven't had Bluetooth on, it's definitely off
    2) I've got two of these apple mice and they both behave the same, so I doubt it's a cable issue
    3) The problem eases most times when I change the USB socket but then seems to get worse again
    4) Ho do I revert back to 10.14.4?
  6. SecuritySteve macrumors 6502a


    Jul 6, 2017
    If you have a backup from before you updated, you can use that. Otherwise you can't. I probably should have mentioned that. :(
  7. mikehalloran macrumors 65816

    Oct 14, 2018
    The Sillie Con Valley
    A recent OS update causing a problem is one of those things that entitles you to talk with Apple Support. Go to the support pages and schedule a call back.

    How old is your iMac?

    I was once on the horn with Apple Support with a USB issue and it was the third attempt to reset the NV RAM that did it. He was just as surprised as I was.

    If the mouse is connected through a hub, try a direct connection.

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6 May 29, 2019