Yosemite keyboard not working

Using the on-screen keyboard, the Caps Lock (and all other keys) work just fine on the Apple USB keyboard, so it's not like it's broken. Also, plugging in another keyboard (generic usb keyboard), after 10.10.3 it works fine (Caps Lock light is working, too).

I have been using the keyboard without a USB extension and with other USB cables plugged in since my last post and to date all seems to work well except that the LED on the num pad will not light up. I tried my other Apple keyboard today to write this reply. It is the white version of the one I mentioned above and have been using and was not working either when I wrote the previous reply. It is now also working with the exception that the LED will not light up on the num pad. I am writing this post with the white keyboard plugged in directly to the iMac using OS X 10.10.3. It seems to be working normally. Not sure what original case was or what is stopping the LED from lighting on both the black and the white keyboards but at least they work.

The num pad not lighting is bugging me but I'm getting over it.

Hope you are all having better luck as well.

OK! Guys, since speaking to an Apple tech online, I did the following and I've had no issues with the keyboard since. This has though only been for approximately 3 days. Hopefully it holds out!

I disconnected the power cable from behind the Mac Pro tower. Left it for a minute and then reconnected it. Turned the Mac on and voila, no problems. I believe this is called "resetting the SMC".

But like I said, this has only been trialled for around 3 days. And this problem is very random!

Another thing I was told by the Mac tech was that maybe the problem occurs every time the monitor goes to sleep. This may be causing some sort of problem. When I get the time I'll try putting the monitor to sleep then restart the mac and see if the keyboard still works.

I have tried all the options mentioned here, but still nothing. Keyboard works fine on a windows computer and on a mac mini server but won't work on my yosemite mac pro. Has anyone found another solution yet?

I erased my hard drive and reinstalled Yosemite. I still have the issue at random times, and I only installed two apps on the system: Photoshop and Illustrator. I doubt those are the cause, but I had to install them right away to keep working.

Erased hard drive, reinstalled Yosemite (no other software installed): I still have the issue.

Well, a few weeks in from my trial and the keyboard with my Mac Pro (tower not laptop) is still hit and miss. Sometimes they keyboard works fine connected to the monitor and sometimes it doesn't and I have to connect it to the tower.

Ridiculous!

Resetting PRAM seemed to help me.

I have wired USB keyboard,

I had recently upgraded to 10.10.3 from 10.9.5 and was having reproducible keyboard hangup with repeatedly using caps lock key. Affected my wife more than me with her typing style, but if she's not happy and computer keeps crashing than nobody's happy.

Anyways for now the problem seems to be gone.

Yay - thanks so much for that - just plugged external drive into usb on keyboard and now I've got a power light on my wired keyboard and all functions back.

I upgraded my Mac Mini to 10.10.4 yesterday. Ever since, whenever it goes to sleep the keyboard stops responding. Restarting doesn't help. The only thing that seems to work is unplugging and replugging the keyboard.

Yes me too (on MacBook Pro). Afterwards 4 yosemite updates later the issue still exist. It's so randomly to get the keyboard responding again.. Often I have to unplug .. plug an old PC keyboard and replug the APPLE keyboard. it just annoys the heck out of me!

Plugging in iPhone to USB port on my Apple wired keyboard did the trick for me too....thanks!

Using the extension which I had also stowed away did the job. Wondering if the plug was faulty but had a snugger fit into the extension end?. Luckily I had another device to investigate the issue. Thanks for you posting.

I used the keyboard with an iMac and with my MacBookPro and it worked fine. But for some reason when I tried to use with the MacPro of my office it doesn't work. Then I tried the same things that every one written here, and the only one that functioned were that the hake0305 did. Then I plugged my iPhone into the keyboard and the keyboard was detected and started to work.

Recently I sent to diagnose the MacPro to an Apple Care Center, thinking that it was malfuctioning. But when I discover this forum I see that the problem is the combination of the keyboard and the MacPro Computer. Because I'm using another one MacPro computer meanwhile mine is on service and I have the same result. The new one computer doesn't work with that keyboard and other computers can do it.

I think that the problem is the combination of that keyboard and the MacPro computer, because the iPhone pluggin reactivate the keyboard.

I sent the office computer to service and the serial number is: F5KPM07PF9VN and in those days the service care center will return the answer about the computer problem.

You can do something about this, because is a time loosing.

Many thanks.

Go to System Preferences > Accessibility > Mouse and Trackpad

Turn off "Enable Mouse Keys" button. Your 10-key is working, it's just moving the pointer around pixel-by-pixel, instead of inputting numbers. You're looking at the cursor while your pointer is doing its rendition of Riverdance.

Switching on and off a lot of stuff in here will improve performance on input peripherals, including the Magic Mouse. For example, the setting to ignore the built-in trackpad when you have an external pointer attached to the system is in here. Because of course you wouldn't want that under Trackpad or Mouse where it's been forever, and where one would logically go looking for it.
Monkeying around in here will also fix a problem that is in Yosemite, if not earlier, where your pointer won't budge on the trackpad, or only moves up and down on the screen. Well, it doesn't FIX it. It just patches it for a while until you install a font while Safari is open, after which you may need to shut everything down, repair permissions, and reboot.

Because Safari really, really needs access to each and every font you install on the system.