external mac keyboard not working with maverick on macbook air

This is so ridiculous. I just got my new keyboard from apple (40$) 2 months ago (the original one stopped working). It was working fine until today! I unplugged it to clean it. I used a cotton with a little alcohol. after I plug it back in and I WILL NOT WORK! ***! I tried the extension trick, nothing. Plugged it in my Mac Book Pro, nothing. This is so frustrating.

Well today I plugged the KB back in to see what would happen and at least I can type something but most of the keys don`t work so know I know the only solution is to go to an apple store. But I assure you I won`t get a new one. Something electronic happens when unplugged and plugged back in. The truth is in ends up being a piece of trash. Good luck everyone.

Had the problem ever since updating my MBP13R (late 2013) to El Capitan. After plugging in the (2 month old) keyboard would not work and after a series of random events it would start working again, but only on the right side USB port. It must be connected to the powered USB port. The caps lock light would not come on.

But indeed, the extension cable did the trick!

The USB controller is the computer chip that manages the USB ports. If it doesn't get enough power, yes any device that depends on the computer for power is likely to have issues. Furthermore, the issue people are experiencing here are typically with third party devices, but as is apparent Apple is not immune to this. Energy Saver is one big culprit in bringing the lower powered USB port down to even lower power. This may be a greater problem when Macs become at least four years old and their PRAM battery or capacitor deteriorates, or their main battery starts to deteriorate if it is a notebook. It is always helpful if you have more than one USB port to try another, or also to try a wall powered USB hub to see if it makes a difference.

Well, well. Stubborn me I got an old extension and tried it and it worked on both my MBP and my iMac. I even plugged the "damaged" KB directly to my cinema without the extension and it is working fine. What happened? I wont even try to find out but one thing is for sure, something happens when the KB is disconnected so do not disconnect the KB with the machine on. And somehow the error got fixed by itself or maybe the old extension reverted the damage. Good luck everyone. Meanwhile I`m happy I got my KB back to normal. Cheers!

Yeah, this issue has been around for far too long now! It started in Mavericks seemed to go away in Yosemite after several updates but now back worse than ever in El Capitan!

I have done all the trouble-shooting exercises, which sometimes work for a short period of time and then back to connection loss. I need the USB keyboard with extended pad for work and thought of picking up a bluetooth extended pad to go with wireless keyboard but that thing loses connection as well as the magic mouse, although not nearly as frequent as the USB keyboard.

It really is a shame, I used to be a proud Mac Pro user but I am really losing faith in Apple these days,

Just adding my issues to the mix to document my similar problem. External keyboard is intermittent when using both my MBP and through my Thunderbolt display. These products have lost their "they just work" magic. They "just don't work" and I don't have the time or patience to waste trouble shooting.

This also happens with a Mid 2015 Macbook Pro running OSX Yosemite (10.10.5). I had this problem with the full Apple keyboard (with numeric keypad) directly connected to the Macbook with no other USB devices attached. I did have two external monitors connected, though I don't expect that would make a difference.

If the Genius bar geeks suspect a USB hub power supply issue provide they could provide the expected specs so that we could test our particular machines.

I am also having this problem. I bought my mid-2015 machine around December and had issues with the USB ports not being responsive to the Apple external keyboard.

My Logitech mouse is plugged into the keyboard and the keyboard is plugged into the MBP.

If the machine falls asleep, and wakes then the keyboard and mouse don't work.

If I remove the mouse from the keyboard and plug in the mouse by itself, the mouse works.

If I plug in the keyboard without the mouse, the keyboard still does not work.

The current solution I have is a full shutdown on the machine and starting it back up with all peripherals detached.

Reattaching them after I log back in gets them to work.

I have upgraded from Yosemite to El Capitan and the issue is still there.

I did not have this issue with my old MBP 2009.

Just swapped 6GB of RAM into a neighbor's April 2008 iMac (it had the stock 2x 1GB SODIMMS) and then upgraded the OS to Mavericks. Apple USB keyboard not recognized, though USB mouse connected to keyboard USB port was recognized, as was a thumb drive with Disk Warrior 5.0. So, it wasn't the USB ports (switched ports just to make sure). Also reset the SMC--still no response to the keyboard, though the iMac kept asking for a Bluetooth keyboard! So...with the help of this wonderful thread, I put a USB extension cord in-between the USB keyboard and the iMac, and voila, just as with the rest of you, it worked! Updated Mavericks (I had installed the original version from an image on a thumb drive), and now it works without the extension cord in the middle. Thanks everybody; this was a huge help!

Well, well. Stubborn me I got an old extension and tried it and it worked on both my MBP and my iMac. I even plugged the "damaged" KB directly to my cinema without the extension and it is working fine. What happened? I wont even try to find out but one thing is for sure, something happens when the KB is disconected so do not disconnect the KB with the machine on. And somehow the error got fixed by itself or maybe the old extensin reverted the damage. Good luck everyone. Meanwhile I`m happy I got my KB back to normal. Cheers!

Today I discovered this thread. I'm having troubles connecting my (wired) keyboard since 2013. Tried resetting NVRAM, PRAM, everyting.... but unfortunately nothing worked. Until adding an extension cord 🙂. Now let's hope it KEEPS working. I've read stories that it's just a temporary "solution".

Thanks! I have a similar problem.

Mac Book Pro, Late 2013

Various Apple Keyboards, directly connected via USB.

OS X Mavericks and Yosemite

Effect: Keyboard and devices attached to the keyboard stopped after start/restart/wakeup randomly (sometimes it worked fine during weeks, sometimes I spent up to hour until it worked again). Plugging out and in again worked often, but not always. Just waiting worked sometimes, but mostly not.

The extension cord trick currently works, let's see if this works during a longer test period...

I'm having the same exact issue with my IMac. The extension cord trick didn't work, so I'm not sure what to do next. Based on what I'm reading here, I'm wondering if it has something to do with the El Captain update. Should I uninstall it?

Add another to the list. Late 2014 Retina iMac and just had it happen again for the 3rd time in about a year. Have an external Apple monitor through Thunderbolt that has a couple USB ports on it and moved the keyboard over to that to get it working again. In a couple days I can plug it back in to the main iMac and it'll work again.

I had just unplugged it to clean the keyboard and couldn't get it to work in any USB port on the iMac afterwards but works fine on the external monitor. Latest OS, Apple USB Extended Keyboard. Incredibly annoying, but happy to have found this thread again (I had forgotten how I'd gotten it to work again previously).

iMac (Retina 5K, 27-inch, Late 2014)

10.11.4 (15E65)

Keyboard A1243 - Apple USB Extended Keyboard