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Thunderbolt Display does not accept USB keyboard

I have a Macbook Pro which I use in combination with a Thunderbolt display. I also have a standard Apple USB keyboard with numeric keypad which is plugged in one of the USB ports of the Thunderbolt display.

The problem I have is, that the keyboard is often not recognized. Usually when I shut the laptop down and start it again. I usually managed to bring it to work when I unplug the keyboard several times and plug it in again OR I open the settings and wait for some time and do random things.

I don't have any problems when I just put the Mac to sleep. The keyboard will still work when I wake the Macbook up again.

The keyboard works perfectly well when I connect it with the Macbook directly - so it seems not to be an issue with the cable. Other USB devices work in the ports of the display - so this seems not to be the issue as well.

But of course I want it to work with the display so that I don't have to unplug too many things to take my laptop away.

 

I followed the advice of a poster in the Apple forums, and used a USB extension cable between the keyboard and thunderbolt display. It fixed the problem for me, and no-one seems to know why. It might be something to do with changing the cable's impedance, or maybe it's a bus timing issue. Either way, it worked for me.

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A late answer because I only just had this problem!

So I did everything in all the other posts I could find on this [MBP Retina 15" Intel Core i7 Moutain Lion (10.8.4) - twin Thunderbold 27" screens]:

  • Unplug everything
  • Turn everything off
  • Wait 30 minutes (not seconds)
  • Tried all combinations of re-plugging and re-powering up
  • Tried all combinations of re-start / sleep / wake
  • Tried SMR reset & PRAM reset

All to no avail.

And the key board worked fine plugged into the MBP - so it had to be the USB port, right?

But wait!... another identical keyboard plugged into the USB port worked just fine :S

So, my solution (fwiw):

  • I unplugged the USB keyboard and walked away for an hour
  • I did absolutely nothing else
  • I plugged it into the same USB socket on the same TB monitor
  • And it worked!... I am typing this on it now.

Go figure! My take is that there is some sneaky circuitry in the keyboard that's at fault and all the attention has been on the USB port (where mine was too!)

Hope this helps others who may be searching on this very problem, as I was.

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I discovered that when I plug the USB cable of the keyboard into the short USB extender cable (that came with the keyboard) and then plug the extender cable into the Thunderbolt display, it works for me. Maybe it will work for you too.

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