external mac keyboard not working with maverick on macbook air

I would be interested to hear what you learn after they run diagnostics. But, for what it's worth, I first experienced the problem with my late 2011 13" MBP after upgrading to Mavericks and also on my new 13" MBP Retina. The problem did not manifest itself before moving to Mavericks which leads me to feel this is a firmware/software issue and not hardware. Just my 2-cents for what it's worth.

As to why simply adding a short USB extender fixes the problem is a mystery. Would love to find out what the final analysis reveals.

I think you are right...it's not hardware. But I have a 3 day old computer here and I'm going to let them document the problems and make sure they fix it.

I plugged my keyboard into my wife's MBP (13" not retina) that we bought in January. The keyboard didn't work at first, then started working. The funny thing is that my old, clunky plastic keyboard that's probably close to 10 years old works just fine in both!

I'll report back tomorrow.

Sorry to disagree. But just the fact that the keyboard works when an extension cable is used and not when it isn't means FOR SURE that there is a wiring error in the keyboard plug which makes the computer not always recognise it. On top of that I have been told to take my keyboard in to a shop for [words indicating a replacement], so Apple know there's a problem too but just won't advertise it for fear of a rush for a free swap from the rest of the planet

Yes, it possibly could be a keyboard issue but why would that same keyboard work without problem on the same MBP with Mountain Lion but fail after upgrading to Mavericks? Inquiring minds.....

Did you visit to the Genius Bar result in any more information?

My visit to the Genius Bar was quite eventful, but ultimately provides no information as to why the keyboard wasn't working unless an extension was used. The short story:

I shut down my computer and head to the genius bar. I arrive early, so decide to do 1 last time machine backup. After hitting the power button, my computer freezes on the grey screen and refused to start. Apples's solution to all the problems: new keyboard and new computer. 3hrs of data transfer later, and my problem is gone....but still no answer why the old computer/keyboard didn't work.

Man, bummer about your new Mac but glad they could replace and get you going again. From your description, it sounds like the also replaced your Apple USB keyboard. Did that resolve the USB issue? If so, I am going to ask for a replacement keyboard.

Yes, the new computer with a brand new keyboard is working fine.

I've been to the Apple store, they replaced my keyboard with a new one and the problem has gone away. The new keyboard works fine.

It worked for me too...but I had to connect the extension straight into the computer for it to work...it would not work from my apple cinema....thanks

I now have encountered this problem, but my keyboard worked fine in both USB ports on my Mac Book Pro 13" w/ Retina, OS 10.9.2 since I purchased the machine in October 2013. Now the Apple keyboard only works in the USB Port upper right next to HDMI connector, and no longer functions in the left USB port next to Lightning connector.

I have only applied application level updates, iMovie, Safari, etc in the last 10 days.

Adding the USB extension solves the issue for the left USB port and keyboard functions, as others have noted.

As an electrical engineer, it is obvious to me that we are dealing with either a power issue or timing issue that is software based.

Why isn't someone from Apple Support posting on this thread?

Thanks

MK

I don´t know. I´m confused. My KB doesn´t work neither on my iMac nor my Mac Book Pro. That tells me something happened and the KB stopped working. My iMac has Maverick and my MBP 10.6.8 "Snow Leopard". I wish I was in the US to be able to go and change it for new one but I´m in caracas and that´s not possible here. I´ll wait and see if Apple gives an answer. They should, this KB is worth $80. Not chip! Anyway thanks for your comment.

It looks like a motherboard issue. Apple will send you a box and you send your mac back, and it's very fast to get it back.

It can´t be a motherboard issue on both computers at the same time...come on!

Adding myself ot the list of people that has experienced this issue. (Late 2012 MBP 13" and external Apple USB keyboard)

I tried all kinds of things, and couldn't get it the USB keyboard to work. However, as soon as I added a USB extension to the keyboard it started working. It wasn't even the extension that came with the keyboard either. It's just some generic USB extension I had laying around.