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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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Posted on Jul 17, 2013 9:37 AM

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

116 replies

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!

Mar 2, 2013 12:46 AM in response to Prag mac´ tic

I got the same problem as described above by many users my setup (MacBook Pro, Thunderbold Display and Keyboard with NumericalPad). Lately it seems it gets worse, nearly every time the it comes out of the Sleep mode or is even turned on the key board is not functioning at all. It takes a few times to un-replug it to get it working (what a hassel). Not even unplugin the dispay itself helps anymore.


As it seemed the problem exists for a long time... the updates have in my case just increased the frequency of the problems. I though these times are over, but I guess could switch back to a Windows there the hardware is working at least :/

Apr 15, 2013 3:47 PM in response to Prag mac´ tic

Just to add, this issue seems to extend further than the USB bus. I have a thunderbolt-interface external hard drive, used for Time Machine, connected to the Thunderbolt Display (firmware ver 22.2). I also have an extened USB keyboard connected to the Thunderbolt Display. Plugging my MBP Retina (OSX 10.8.3) into the Thunderbolt Display and having EVERYTHING wake up from sleep happens 25% of the time. I always eject my external drives before disconnecting, and administered all the appropriate updates. Can't think of anything else, will be calling Apple.

Apr 22, 2013 5:58 AM in response to Prag mac´ tic

Similar symptom.

Hardware:

1. Macbook Pro Retina (15"), Mid 2012, 2.6Ghz i&, 16GB RAM, OS X 10.8.3

2. LED Cinema Display 27" USB Hub Version 1.0 Version 2.99, Display Audio Version 1.2, Display iSight Version 2.61, Keyboard Hub Version 96.15

3. Apple Keyboard with Numeric Keypad - English (USA) (USB) Version 0.74

4. Apple Wireless trackpad. (previously used Wireless Apple Magic Mouse with same symptom)


I use the macbook on trips and typically enter sleep mode by closing the top cover (display). When I return I connect the macbook pro to display by connecting LED Cinema Display connections in this order; 1. Power (adapter for new power connector) 2. Mini display port 3. USB (on left side of MBP). I use the track pad to wake up the macbook.


Unpluging keayboard from back of Display works sometimes. Other times I have to open the laptop and reconnect to get Apple USB keyboard to work.


Trying to toubleshoot this AM I connected as usual and verified the Apple USB keyboard was unresponsive. Opened the macbook cover and then opened System Information -> Hardware ->USB.

Under USB Hi-Speed Bus ->Hub I could see: 1. Apple LED Cinema Display, 2. Display Audio, 3. Display iSight


After going through workaround to get Apple USB keyboard to work I now see Keyboard Hub and under that Apple Keyboard displayed in System Information. (Requires that you close window and click System Report)


Complete listing from System Information

System Information -> Hardware ->USB.

Under USB Hi-Speed Bus ->Hub I could see: 1. Keyboard Hub -> Apple Keyboard 2. Apple LED Cinema Display, 3. Display Audio, 4. Display iSight


Looks to me like the Apple LED Display Keyboard Hub is not being initialized properly.

Apr 25, 2013 9:43 PM in response to PapaBoucher

Hi everyone, I think I might have a solution - convenient and cheap:)

I've had a similar problem - my Apple keyboard would sometimes work, sometimes it wouldn't, sometimes I had to plug/unplug or plug in another device for it to work.

But one day I was doing some organizing with all my spare or unused cables and I'd found I have 2 spare Apple USB cables. I thought it's a shame that they're wasting away:), so I figured I could use one for the keyboard - didn't really need it, but few extra CMs couldn't hurt. And since I've connected the keyboard via the extension cable my problems with TBD were GONE! Finally! I've used this set up for over 2 weeks now and had no problems. The keyboard works everytime right from the boot up and also after sleeping and then waking up my MBP. I've also checked that when I unplug the extension and plug in the keyboard directly the old problem returns.

Thus I encourage everyone having this annoying USB problem to try an extension cable for the keyboard.


Hope that helps you guys.


Take care.

Apr 26, 2013 9:39 AM in response to Prag mac´ tic

This may not help everyone, but what worked for me was that I discovered the external screen will light up even when the plug into the MacBook is not properly seated. For some reason only the keyboard (plugged into the monitor) failed to respond. Going through the helpful suggestions above I noticed that the plug (video to MacBook) was not snug, so I pushed it in further, and then things worked normally. I would not have expected the video to come up at all, but apparently this connection is quite picky about the tiny little electrodes. I hope this helps someone, as this forum has often helped me over the decades.

Jun 16, 2013 11:45 AM in response to chris panas

Well as crazy an idea as I though extending the cord lenght was, I gave it a try. After many in home tests and 5 seprate trips away from the home office and back again I have yet to have the keyboard fail to respond properly.


I went so far to troublshoot the issue by looking at System report under Hardware -> USB -> USB Hi-Speed Bus -> Hub (1st instance) ->Hub -> [Keyboard Hub -> Apple Keyboard ]= only appears when system recognizes the keyboard. With the USB extension cable plugged in it connects every time.


Sounds like a timming issue in the display hub or keyboard where extending cable length changes impedance. Cable fix narrows down the issue to most likely being the display hub.


Macbook Pro Retina, Mid 2012 2.6Ghz, 16GB; OS X 10.8.4

LED Cinema Display

Apple USB Keyboard A1243

4ft USB extension cable. Connected to LED Cinema Display (Does not matter which port)


Nice find Chris Panas!

Jun 17, 2013 6:01 AM in response to scoccera

The only consistent solution I've found is to this problem is to get the Apple Store to replace the keyboard. Here's a few things to note:


I work in a business where we purchased 14 Thunderbolt monitors with 14 of the Apple USB keyboards. There were a few keyboards that had various combinations of results with a few different monitors (the symptom described--keyboard doesn't respond when plugged into Thunderbolt monitor and laptop gets attached, yet will work when plugged into laptop directly).


I took the keyboard and Thunderbolt display to the Apple Store where a genius started working various combinations to see if he could recreate the problem. It started working at first, then started showing the symptoms. He tried a different monitor and he tried his laptop and no matter what combination, the keyboard wouldn't work unless plugged into the laptop directly. I asked him to try a different Apple USB keyboard and it worked fine. He then replaced my keyboard.


In short, the keyboard is the only part in the combination that consistently seems to show the problem. When it's hooked into one Thunderbolt monitor, it may not show a problem. When hooked to another, it may show the problem. And sometimes when hooked into any Thunderbolt monitor it shows the problem. I'm not sure what the problem is in the keyboard, electrical or otherwise, but sometimes they just don't work with the Thunderbolt display, period. The other thing is timing--the problem would begin to show around a few days to a week later. I don't remember ever seeing the problem when we first use the keyboard.


Of the 14 keyboards we originally purchased, I returned 3 keyboards for replacements. Of those 3 replacements, I returned 1. In total, 4 keyboards had to be replaced and I haven't seen the problem since.

Jun 18, 2013 10:17 AM in response to scoccera

Intersting. I would be inclined do the same, if it didn't require schlepping the TBD to the Apple store.


This sheds some light on the keyboard problem, but there I still see some quirkyness in waking the TBD.


I have a backup drive connected to the TBD via Thunderbolt cable. This is my Time Machine drive and I expect it to perform backups as necessary when my MBP is connected to the TBD. Unfortunatley, the drive isn't always recognized, even as an external drive. It sometimes requires unplugging and reconencting the Thunderbolt cable to the external drive. Only then will it be recognized and identified as the Time Machine drive. The connection success rate is about 50%.


I'm going to try a different (longer, and Apple brand) Thunderbolt cable between the two, akin to adding the externsion USB cable to the keyboard and see if anything changes.


Anyone else have a problem with other periferals connected thrugh TBD (ethernet, mouse, etc..) being recognized when waking up? Is power cycling the TBD before connecting the MBP the answer?

Jun 21, 2013 1:25 PM in response to Prag mac´ tic

I've been getting this problem for years. Still have it. This time on a Mac Mini with TB display. Was fine for a while, now it's come back the past few weeks. Every time I reboot the keyboard and mouse don't power up and respond. I've found that on the login screen, if I unplug the TB display and plug it back in (with the keyboard/mouse etc still plugged into the back of the TB display) then it all registers and works fine, until the next reboot.


OS X 10.8.4, Mac Mini 2011 quad core.

USB Keyboard Plugged into Monitor Often Doesn't Work

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