iMac High Sierra Upgrade - USB Keyboard not recognized

I have got similar issue with my MacBook Air (2013). Using an extension wire USB or a hub works for me. Maybe I have troubles with physical connection, I do not know, however my keyboard works on other device directly.

What did the trick for me was to unplug the keyboard, put my iMac to sleep (wait for it to fully sleep) and then plug the keyboard back in.

A USB extension cable also brings it back to life but I dont wanna use that solution as it isn't a very elegant one. So I tried to unplug the keyboard, put my iMac to sleep, plugged the keyboard back in and it worked.

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.

After updating my own 27" late 13 model desktop, my USB apple keyboard no longer works either. I've tried resetting SMC, NVRAM, Disk Utility (first aid) and nothing works. The keyboard, when plugged into USB does show up when I look at System Information: USB. It just doesn't work at all. It started off by the space bar not working right after the "upgrade" to High Sierra then died altogether.

I spent nearly 45 minutes on the phone with Apple support yesterday about this issue. Ultimately, they say my keyboard is defective and they're now sending me a new one. I find it interesting that so many people are having similar issues as I did though this was deemed a hardware issue and nothing to do with High Sierra. Things that make you go, hmm.

I am having this issue Late 2013 27" iMac. I'm using a USB keyboard (WASD mechanical). It worked just fine on this computer with Sierra and El Cap before. However, I just upgraded today to high sierra (10.13.2) and after it goes to sleep and wakes up the keyboard won't work until I unplug it, wait several seconds, and then plug it back in (to type in the password). I just tried it out after sleeping and waking on a PC and it was just fine.

Clearly there's an issue with the USB bus after waking. Just a little annoying having to reach back each time it wakes up to do this :-/

I have related issues. Cmd tab doesn’t change apps on my usb extended USB keyboard. I even tried reinstalling High Sierra with no improvement (as advised by tech support). So I tried the magic keyboard that came with the iMac. This fixed it.

Seems to me that there’s a bug in the USB extended keyboard driver in High Sierra.

My best guess is that the testing people did not have a script involving a pre-2014 iMac and model A1243 USB extended keyboards. These keyboards are USB2, so there's likely something hinky with the USB2 controller bus getting legacy signal from the USB controller.

Interesting. So, if that's consistent for multiple instances, then some kind of persistent state about the keyboard is preserving the old/incompatible setting, and once it times out, the up to date peripheral data is added to the USB state? Just trying to imagine how this approach works… and by way of unintentionally/potentially confirming this, last time it happened with me, I just used the Bluetooth keyboard for a day, then tried the USB one again. So far, several days of uptime, no hangs in ~96 hours or so. Fingers crossed.

I am having this problem too, with my older USB Apple keyboard. I updated to the latest version of High Sierra and it stopped working. It works with every other computer in the house, both Mac and PC. I tried everything listed here (reset SMC & NVRAM, run Disk Utility, plug into PC, leave unplugged for a while) to no avail. My newer Apple USB keyboard works fine. Both are A1243 models, but I suspect the newer one has some different internal components that are incompatible with the latest version of High Sierra + my MacBook.

I had this with one of my USB devices. I was able to resolve this today with the purchase of a USB C to USB convertor and then plugging the device into the USB C port at the rear of my iMac.

I went through the Apple Care and Apple tech help procedure and none of the usual things worked. My iMac is only three weeks old. Luckily I have an Apple store nearby who tested my item on display iMacs, item not recognised! However when he connected to a MacBook USB port it popped up on screen and behaved normally much to the surprise of the guy in the store, confused springs to mind.

He went away and came back with said USB C to USB connector connected everything together and the device worked and was recognised by the iMac. I came home with the convertor and everything is now working as it should.

I would add that I have other devices connected to my iMac via the standard USB ports and they work perfectly normally so it is a bit pot luck and frustrating, I suppose you could try my solution to see if it works for you.

Wow. Just wow. Apple really needs to sort themselves out.

A Sierra-loaded (not High Sierra) Mac Pro exhibited similar issues. Just wouldn't recognise an Apple USB keyboard. Plug into a Windows box, gets detected. Plug back into the Mac Pro, hey presto.

We shouldn't have to spend more money to buy USB 2 to USB C converters to make this work! This is madness!

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

Hi, I got the same problem. The bluetooth keyboard that came with the iMac stopped working and got a usb one to replace it. Today after upgrading to High Sierra the Apple usb keyboard just does not work with the iMac so I'm stacked. I tried the usb keyboard with my new MacBook Pro 15" (2017) with upgrade to High Sierra and it worked. My iMac is a 23" 2016.

I having the same issue, I was tring to upgrade from Sierra to High Sierra, after system reboot, I lost Bluetooth keybard, As I dont have a usb Apple keyboard, I tried two different Windows USB keyboard, didn't success. My install process stucks at "Create Account Name", because I can not input any alphabet !!!!!!!

I cannot reset computer params as it needs keyboard assistance... I am in blackhole now.