Help! USB Keyboard not found in late 2012 iMac

[lilface]

I had been away for a week or so, and my iMac was sitting there with no use during that week. There might have been a few short power outages from the snow storms that have been crushing the north east, but other than that nothing has happened.

Went to go do some work on the iMac this morning and my usb keyboard isn't working. I checked to make sure it's plugged in, and I changed the usb ports that it was plugged into, but nothing seems to fix the problem.

Wondering if anyone else has experienced this issue and how to solve it?

Any input would be great, thanks!

 

[fig]

Probably need to narrow down the problem first.

Hard to diagnose without first knowing if the keyboard works on another machine or if another keyboard works on the iMac.

 

[macthefork]

I also had that odd problem earlier this week. An Apple USB keyboard wasn't recognized after shutdown on a Late 2012 imac running ML. I switched USB ports, restarted imac, reset SMC, nothing would work. I thought the keyboard died, since other USB peripherals all were recognized and worked.

So I took that keyboard (that was obtained at time of the 2012 purchase), and plugged it into my mid 2011 iMac, and it worked. I then took the identical model keyboard from the 2011 iMac and tried it on the 2012 iMac, and it worked as soon as I plugged it in.

I still don't know what the problem was. I suppose I should bring the original keyboard that wasn't recognized back to it's 2012 iMac to see if it works now.

You could try simply unplugging it for a few moments and then plugging it back in, which would simulate what I did, or just try resetting the SMC:


Shut down the computer.
Unplug the computer's power cord.
Wait fifteen seconds.
Attach the computer's power cord.
Wait five seconds, then press the power button to turn on the computer.

That won't hurt anything, and may or may not fix your problem.

 

[lilface]

I also had that odd problem earlier this week. An Apple USB keyboard wasn't recognized after shutdown on a Late 2012 imac running ML. I switched USB ports, restarted imac, reset SMC, nothing would work. I thought the keyboard died, since other USB peripherals all were recognized and worked.

So I took that keyboard (that was obtained at time of the 2012 purchase), and plugged it into my mid 2011 iMac, and it worked. I then took the identical model keyboard from the 2011 iMac and tried it on the 2012 iMac, and it worked as soon as I plugged it in.

I still don't know what the problem was. I suppose I should bring the original keyboard that wasn't recognized back to it's 2012 iMac to see if it works now.

You could try simply unplugging it for a few moments and then plugging it back in, which would simulate what I did, or just try resetting the SMC:


Shut down the computer.
Unplug the computer's power cord.
Wait fifteen seconds.
Attach the computer's power cord.
Wait five seconds, then press the power button to turn on the computer.

That won't hurt anything, and may or may not fix your problem.

I did some more researching to see if anyone else had the same problem and I found a few threads on the apple forums.

It looks like there is something faulty in the USB plugin of the keyboard. Many mentioned that they plugged the keyboard into the USB extension cable that it came with and then plugged into the iMac and that seemed to fix the problem.

I tried this and it did indeed fix it. The keyboard is now working fine. So weird.

Hope this works for you too!