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USB Keyboard Plugged into Monitor Often Doesn't Work

Very often the USB keyboard plugged into the 27" Thuderbolt Display will not be recognized. It can be worked around by plugging the USB keyboard cable directly into MacBook Pro (which always works) but the whole point is to leave the office desktop peripherals connected to the monitor when the laptop is taken away. The keyboard is a new Apple full size USB US keyboard with integral numeric pad.


17" MacBook Pro late 2011, Lion (now 10.7.3) always up to date with all Apple software and Firmware, including all the Thunderbolt Firmware updates. The problem has been occuring since 10.7.1 or 10.7.2 (sorry, can't remember exactly what we started with but it definitely predates 10.7.3).


A temporary fix can be achieved by performing an SMC reset but the problem recurs afterwards episodically upon a subsequent instance of the computer being detached from the monitor and then reconnected.


Attachment/detachment (computer to monitor) can be either while machine is off, on, or asleep and the behaviour is the same.


Everything, all powered devices, are conencted to a new UPS with AVR and active power factor correction CyberPower CP1500PFCLCD and no events are being logged (that is, logging is active but nothing has occurred).


Thoughts, suggestions, other data about set up that I ought include?


Thanks in advance for any enlightenment.

Thunderbolt 27" Display-OTHER, Mac OS X (10.7.3)

Posted on Feb 14, 2012 4:33 AM

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Question marked as Top-ranking reply

Posted on Jun 17, 2017 11:03 PM

I share a workstation with my partner, he has no issues with the keyboard, but I was going to buy a new bluetooth one just for me, because it was really frustrating.



My fix: while everything is plugged in, in place and on, unplug the cinema display from the power outlet, & plug back in.


so far this is the only consistent fix for me

116 replies
Question marked as Top-ranking reply

Jun 17, 2017 11:03 PM in response to Prag mac´ tic

I share a workstation with my partner, he has no issues with the keyboard, but I was going to buy a new bluetooth one just for me, because it was really frustrating.



My fix: while everything is plugged in, in place and on, unplug the cinema display from the power outlet, & plug back in.


so far this is the only consistent fix for me

Jul 17, 2013 9:37 AM in response to nbalcom

So getting a longer monitor cable will fix this? Seriously?

No a monitor cable, a USB cable to the keyboard. I was one of the original poster's on this thread experiencing this problem for well over a year. Two weeks ago I finally tried what I thought was the world's stupidest solution: using the USB extension cable with the keyboard. I had refused to believe that was a possible answer. But I can say after two weeks of use (I connect and disconnect my closed Air at least twice a day to a TB monitor with USB keyboard) the keyboard has worked EVERY TIME when plugged into the TB monitor's USB hub with the extension cable.


While its a weird and inexplicable solution (seriously, an extra two feet of cable adding signalling latency???) I can confirm it has worked for me. I guess I should stop trying to believe I'm smart and just listen to other people's solutions more often 😉


Cheers,


--Kaz

Jul 21, 2017 9:36 PM in response to cjnewman

I'm having this issue with a brand-new mid-2017 MacBook Pro 13" USB-C to Thunderbolt Display 27". I never had this issue ever with my 2013 MacBook Pro 15" Retina. AHHH driving me nuts! What's worse is that unplugging the keyboard and plugging it back into the same port doesn't work, I have to alternate which port it's plugged into on the monitor, then it works fine. Power cycling the display doesn't help.


APPLE PLEASE, THIS IS EXPENSIVE STUFF FIX IT.

Feb 19, 2012 4:20 PM in response to Prag mac´ tic

You mention issues with a USB keyboard connected to your Thunderbolt display, do you also have anything plugged into the keyboard? If so unplug all devices from the keyboard and see if it helps.


In my case I was inadvertently trying to draw too much power from the USB port on my keyboard (and indirectly the display). The USB ports on your MacBook Pro can provide upto 2000 mA each, the USB ports on the Thunderbolt display can provide upto 500 mA each and the ports on the Apple USB keyboard can provide only 100 mA. Moving my Wacom tablet from one of the USB ports on the keyboard to a separate port on the Thunderbolt display has resolved the problems I was experiencing.


For fuller details see:


https://discussions.apple.com/thread/3524526?answerId=17541133022#17541133022



Andrew

Dec 3, 2012 12:37 PM in response to Prag mac´ tic

I can offer a pragmatic approach to making it work, though it's not really a "fix."


I summary, if I walk into my office and plug in my Thunderbolt monitor without opening my MacBook Air, odds are none of the attached USB devices or Ethernet will work.


"Solution":

  1. Open the laptop and wait for the screen to come up.
  2. Plug in the Thunderbolt
  3. Wait until the Thunderbolt screen begins to come up (blue at first), and close the laptop.


In my hands, all the devices connected to the Thunderbolt monitor now work every time.


It's a pain in the arse, but until Apple fixes the problem for real, it's a practical work-around.

Feb 27, 2013 11:59 AM in response to Prag mac´ tic

Hi Everyone,


This just seemed to work for me. Try this:

  1. Unplug the Cinema Display from your Mac, if it is connected.
  2. Unplug all peripherals from Cinema Display, including keyboard. You do not have to unplug the display.
  3. With the Cinema Display cord, attach the MagSafe adapter FIRST
  4. With the Cinema Display cord, plug in the USB jack into your Mac SECOND.
  5. With the Cinema Display cord, plug in the DisplayPort into your Mac THIRD.
  6. Lastly, plug the external keyboard into the Cinema Display.


Hope that helps!

Jul 8, 2013 7:41 PM in response to Prag mac´ tic

Hello,


Just reporting that this happens to me as well. It happened to me for the 1st time today and I landed here after a Google search.


I bought my brand new Thunderbolt display yesterday, replacing an LED display (3 years old).


I took my laptop to work today. I came home and plugged in the power and Thunderbolt connection (the computer was asleep from having the lid closed).


Nothing. No keyboard input. I removed it from the back of the monitor and blocked it back in. Still nothing.


I plugged into the Macbook Pro directly on the left side USB. Started working perfectly.


I plugged in back into the Apple Thunderbolt display. Nothing.


I checked to see if I have the latest Thunderbolt drivers. I do. No updates. And the 1.1 version you can manually apply told me that I didn't need that update.


I then hooked up the provided extension cable as suggested in this thread. Plugged it into the Thunderbolt display. It came up just fine and I'm typing up this note


Very strange. I'll do some additional experimentation over the coming days as I transport my Retina MBP to and from work all the time.


Key Hardware:

  • My keyboard is the Apple Keyboard with Numerical Keybpad - English (USA).
  • My monitor is a 27 Thunderbolt.
  • My laptop is this year's Retina display Macbook Pro.


Bus use - for reference:

  • I have an Oxygen 61 key Midi keyboard on 1 of the other USB ports from the monitor
  • I have a Lacie Thunderbolt storage on the Thunderbolt chain from the montior
  • I have (or try to have?) the Apple keyboard from the monitor
  • I have a Duet by Apogge (the original) on the Firewire port from the monitor


David

Jan 23, 2015 3:25 PM in response to Prag mac´ tic

I messaged earlier about this, but after some time I can give an update.


I think I can say with certainty that the problem is limited to the keyboard itself. I don't know what it is, but there's a percentage of the keyboards out there that are bad. Maybe the ones they're selling now have been fixed for this, but I know when I had the problem and the keyboard was replaced with another Apple USB Keyboard, it would work. Below are some points regarding this.

  • I have 14 Apple Thunderbolt displays and Apple USB keyboards in my office
  • When we first hooked them up, they were showing this issue, we tried various combinations of rearranging keyboards with monitors, using extension cords, etc. As a result I saw a lot of strange results -- a keyboard would work fine with one monitor but not another, some worked perfectly well with every monitor, etc
  • I took a Thunderbolt display and keyboard to the Apple store for a genius appointment. At this point I still wasn't 100% on the keyboard being the problem. After changing around the cables with other pieces of hardware including his own laptop, he saw that at different times when plugging and unplugging the cables the symptoms would show or not show. At one point he looked like he'd been told the world wasn't real. After that, it was decided that the keyboard was the problematic piece of equipment and to try out a replacement.
  • I took back to the Apple Store and got replacements for about 4-5 keyboards (if I'm remembering correctly) out of my original pool of 14 keyboards. Horrible percentage -- but people would never notice the problem with the keyboard as they work perfectly fine unless plugged into a Apple Thunderbolt monitor (and there was no guarantee of that since another of the same monitor would work).
  • It's going on three years later and there hasn't been a problem with any of the keyboards or monitors since that time. Some are using the extension cable, some are not.

In short, I think the issue can be isolated specifically to the Apple USB Keyboard and if you try replacing it with another of the same model, the issue will go away.

Feb 19, 2012 4:43 PM in response to andrew.lee

Andrew,


Thanks to the Apple cordless Bluetooth Magic Mouse we are using with this setup, no, there is nothing at all plugged into either of the USB ports of the keyboard.


At various times we have had plugged into the Thunderbolt monitor an external USB hard drive (operated by its own independent power supply), a USB scanner (self powered by 120V ac and not drawing power from the bus), and an ethernet cable to the network.


During testing we removed all of that for an interval sufficient to prove that the problem occurs with nothing else plugged in except the keyboard. Incidentally, all of these peripherals operate normally when plugged into the MacBook Pro directly and they all functioned normally with the previous MacBook Pro (which had no Thunderbolt display but rather the older 23" Cinema Display with the Acrylic trim (we've come a long way <grin>.).


Thanks for the idea but that doesn't appear to be what's happening here (unless the keyboard is somehow defective in some weird excessive power drain producing way). It does work normally when the keyboard is plugged directly into the MacBook Pro.


Other thoughts?


Appreciatively,


Bob

Feb 21, 2012 6:48 AM in response to Prag mac´ tic

I have exactly the same problem with my Macbook Air and the Thunderbolt display. Not only is the USB keyboard unrecognized when I first plug my Air into the display, but neither is the ethernet cable. The ethernet used to work, but no more. Unplugging and replugging the keyboard fixes its problem, but the ethernet seems to be gone for good!


This is sounding like a serious problem. The question is, is it a hardware problem or a software problem?


If it's hardware, I want my money back. This is the same sort of nonsense I had to put up with in my age-old Lenovo and Windows. I don't expect to have to deal with it from Apple.

Mar 18, 2012 1:36 AM in response to Prag mac´ tic

MBP 15" late 2011 2.2GHz 8GB ram Lion 10.7.3 with 27" TBD having same issues with loosing Apple Extended Keyboard connected to display USB but will get it back by simply unplugging and replugging. This is an intermittent problem. Also occurred with a mouse which I started using USB on the MPB direct in closed clam shell mood. Mouse has been working fine now. I also have two hard drives connected to the display one USB and one Firewire. Have also used USB on display to sync and charge iPhone all seem to work and so does keyboard for great lengths of time. Then it will occur loss of keyboard for no apparent reason either in the middle of surfing or coming out of sleep. Apple Care advised plugging keyboard to MBP direct to isolate that it is not a bad keyboard as well as trying update and resets. They also advised that they are working on it. I have updated software for display so that isn't it. So far keyboard is doing fine connect directly to MBP and not the display as it was design for as a dock unit. We will see and report results, just did this earlier today.


Hopefully they will resolve issue so we can use our Thunderbolt Displays as docks as they were design to do!

If anyone has similar experiences do share.

Dave,

USB Keyboard Plugged into Monitor Often Doesn't Work

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