iMac High Sierra Upgrade - USB Keyboard not recognized

I updated my Late 2013 27" iMac to High Sierra (from Sierra) last night. When the install finished, My Apple USB wired keyboard (with number pad) didn't appear to be recognized. I tried unplugging the device and plugging it into a different USB port with no success. The keyboard had been working just fine under Sierra. I rebooted the machine with the same results. The keyboard does work on another iMac of the same vintage (but running Sierra). Can anyone point me to a fix for this situation? I have no other devices plugged into the USB ports. My Bluetooth Magic Mouse works fine, but I prefer the wired keyboard with the number pad.

iMac (27-inch, Late 2013), OS X El Capitan (10.11.1)

Posted on Sep 26, 2017 7:32 AM

53 replies

Jez DK

Level 1

10 points

Nov 22, 2017 10:04 PM in response to Colin Mccannel

Unplug your wired keyboard (leave your Mac turned on) and leave the keyboard unplugged for a couple of hours. Then re-attach and hey presto - it works again.

Nov 24, 2017 12:12 PM in response to Scott Watters1

Also happens here since updating to Sierra on 3.5GHz 6 core. I have to plug in an out now to use my keyboard.

Nov 26, 2017 6:43 PM in response to Scott Watters1

this is crazy. i tried your Command R fix but it won't see my wireless keyboard. i have to get to the log in prompt each time to reconnect it? is there some other fix?

Jez DK

Level 1

10 points

Nov 29, 2017 10:15 PM in response to Scott Watters1

Simply unplug the usb-keyboard for 3-4 hours (leave the Mac on) - then re-insert and it will be recognized again. Don't bother resetting PRAM etc. etc.

Tavecosh

Level 1

4 points

Dec 9, 2017 9:29 AM in response to cglenn2000

Did the new keyboard resolve the issue?

fhritz

Level 1

8 points

Dec 28, 2017 11:14 AM in response to Scott Watters1

What has sometimes helped: switch off WIFI. try to connect Bluetooth device, then switch on WIFI.

Jan 3, 2018 9:59 PM in response to Sverrisson

I thought a USB hub had fixed it for me. But it still fails sometimes even then.

eikinaha

Level 1

4 points

Jan 28, 2018 8:00 PM in response to Scott Watters1

I do not know the cause, but this way I could improve it. It is mysterious.

Thank you

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iMac High Sierra Upgrade - USB Keyboard not recognized