Prag mac´ tic

Q: 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, Mac OS X (10.7.3)

Posted on Feb 14, 2012 4:33 AM

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Q: USB Keyboard Plugged into Monitor Often Doesn't Work

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  • by Graek,

    Graek Graek Oct 30, 2013 1:36 PM in response to Graek
    Level 1 (85 points)
    Oct 30, 2013 1:36 PM in response to Graek

    Worked for a few days with the extension, but I ust got back from lunch and the laptop had gone to sleep. It woke up fine, but the keyboard was not being recognized (I had not unplugged the laptop from the displays).

     

    I unplugged the USB extension and plugged back in after a ferw seconds and it recognized the keyboard then. Annoying.

  • by Mr. Luigi,

    Mr. Luigi Mr. Luigi Nov 2, 2013 12:36 PM in response to Prag mac´ tic
    Level 1 (27 points)
    Nov 2, 2013 12:36 PM in response to Prag mac´ tic

    I have a Mid 2012 Mac Mini and a pre-Thunderbold 27" Cinema Display.  Have had the problem expressed in this thread forever.  Unplugging the keyboard from the Cinema Display and replugging always solved problem.  Issue seems most common after shutting down the Mac Mini.  It doesn't happen as often when waking from sleep.

     

    For some reason I never thought to come to the Apple Forum to see if others were having the problem.  That is not like me.  I guess I just got use to plugging and unplugging.

     

    It is GREAT to know I have shared misery.

     

    Thank you.

     

    But, better still.  I just added the extension cable to my keyboard and plugged things back in to the Cinema Display.  My first reaction is that it sounds like Voodoo Pixie Dust Magic.  But previous poster's suggestions that the length of the cable (and the actual extension connector itself I may add) have changed the electronics in significaltly subtle ways...well...hm...that actually sounds plausible.

     

    I promise to test this out and report back to the group with the results. (This discussion thread is now saved to my Safari Reading List.)

  • by Mr. Luigi,

    Mr. Luigi Mr. Luigi Nov 2, 2013 5:27 PM in response to Mr. Luigi
    Level 1 (27 points)
    Nov 2, 2013 5:27 PM in response to Mr. Luigi

    Holy C***!

     

    I shut my Mac Mini off for 5 hours.  Just turned it on.

     

    Keyboard WORKS without unplugging and plugging its USB cable with Cinema Display!

     

    OMG!

     

    I mean...really...fixed by adding the extension cable?!

     

    I won't post again unless the fix doesn't hold.

  • by alokkah,

    alokkah alokkah Nov 3, 2013 2:31 PM in response to Prag mac´ tic
    Level 1 (0 points)
    Nov 3, 2013 2:31 PM in response to Prag mac´ tic

    Hello guys,

     

    I had the same problem and I tried a simple solution and it worked perfect with me.

     

    1- Unplug the Keyborad from both the Mac machine and the monitor.

    2- Unplug the thunderbolt cable from the Mac machine.

    3- Re-plug the thunderbolt to the Mac machine again

    4- Re-plug the keyboard into the thunderbolt monitor

     

    If it does not work fine repeart step 3 with a different thunderbolt port.

     

    Good luck.

  • by trippel311,

    trippel311 trippel311 Dec 22, 2013 9:36 PM in response to Prag mac´ tic
    Level 1 (0 points)
    Dec 22, 2013 9:36 PM in response to Prag mac´ tic

    JUST bought a new retina MBP and a brand new Thunderbolt Display, (12/21/13) and I have the same problem. As evident in this thread, people have been having this problem for two years and Apple has done nothing.

     

    This is part of the basic, fundamental purpose of owning a Thunderbolt display. It's costs $999. For that price, you expect the best. The fact that basic peripherals (and Apple brand ones at that) plugged into it don't work with it, is unacceptable. My solution to this problem is simple, I'll be returning the display.

  • by Mr. Luigi,

    Mr. Luigi Mr. Luigi Dec 23, 2013 6:57 AM in response to Prag mac´ tic
    Level 1 (27 points)
    Dec 23, 2013 6:57 AM in response to Prag mac´ tic

    Ok, I lied. I said I wouldn't repost if the extension cable fix continued to work.  Then I thought some folks would wonder if I just forgot to post that it stopped working.

     

    It has NOT stopped working!  It's been over a month and a half now.  Hundreds and hundreds of of "tests" of the fix.  It continues to work flawlessly.  My keyboard is recognized EVERY time and immediately.  I dealt with this problem for several years and who would have thought that adding a simple extension cable (that comes with the Cinema Display) would so completely solve the problem...at least for me.

     

    Happy Holidays.  Mr. Luigi

  • by GeekTech360,

    GeekTech360 GeekTech360 Dec 25, 2013 12:49 AM in response to Prag mac´ tic
    Level 1 (0 points)
    Dec 25, 2013 12:49 AM in response to Prag mac´ tic

    Can't believe it here either. I was becoming frustrated with a Pre-Thunderbolt Apple Cinema Display I have (24"). The keyboard would stop being recognized and to make sure I would hit the caps lock button to see if the lime green light would come on...it would not. After finding this thread today, I went back to my original box took out the new extension cable, plugged it in to the back of the ACD and presto, it worked. Doesn't disconnect and wakes up the computer also. I've only had this keyboard with numeric keypad for 2 and a half weeks, I was about to exchange it for a new one from BestBuy, glad I found this thread before I did! Christmas Miracles do happen!

  • by EkriirkE,

    EkriirkE EkriirkE Jan 16, 2014 10:47 AM in response to Prag mac´ tic
    Level 1 (0 points)
    Jan 16, 2014 10:47 AM in response to Prag mac´ tic

    I've also this issue with an MPB + 27" Thunderbolt ever since I had it.  The US Device Tree doesn't show the kb, I have been in the habit of repeatedly pressing Caps Lock to see if it lights up (so I know the kb will before logging in, since the login screen can take up to 2 minutes before it responds to keypresses for the password)

    Sometimes unplugging the kb and re-inserting it works.  Othertimes I just keep unplugging everything and replugging it in until it works.   When I'm fed up I move the kb to the MPB directly which always works.

  • by Graek,

    Graek Graek Jan 16, 2014 10:52 AM in response to Graek
    Level 1 (85 points)
    Jan 16, 2014 10:52 AM in response to Graek

    Apart from one time, the extension cord trick (solution?) has been working without fail for over 2 months.

  • by trippel311,

    trippel311 trippel311 Jan 16, 2014 10:53 AM in response to Prag mac´ tic
    Level 1 (0 points)
    Jan 16, 2014 10:53 AM in response to Prag mac´ tic

    Same here. Keyboard extension trick has been working great for me. Never had to return the display

  • by Mr. Luigi,

    Mr. Luigi Mr. Luigi Jan 16, 2014 11:42 AM in response to EkriirkE
    Level 1 (27 points)
    Jan 16, 2014 11:42 AM in response to EkriirkE

    The months keep piling up and the "add the extension cord" trick has not failed me once.  I now consider it a solution.  BTW, the extension cord comes with the display.  Look around in the packaging.

  • by EkriirkE,

    EkriirkE EkriirkE Feb 14, 2014 9:43 AM in response to Mr. Luigi
    Level 1 (0 points)
    Feb 14, 2014 9:43 AM in response to Mr. Luigi

    Using an extension cable did improve the recognition but not 100%.  After 4 weeks of this it has ceased to work again and im back to re-plug & caps check several times until it finally works again.

  • by ghotiing,

    ghotiing ghotiing Feb 14, 2014 9:59 AM in response to EkriirkE
    Level 1 (0 points)
    Feb 14, 2014 9:59 AM in response to EkriirkE

    I had the same experience when I used a non-apple extension.  Using an apple USB extension I have never had the issue reoccur

  • by EkriirkE,

    EkriirkE EkriirkE Feb 14, 2014 11:59 AM in response to ghotiing
    Level 1 (0 points)
    Feb 14, 2014 11:59 AM in response to ghotiing

    I'm using the extension that came with the keyboard. It has a even has a divot that prevents you using it w/ no apple devices.  The workaround no longer works and I have the jeyboard plugged into the MacBook directly now.  The Thunderbolt Display USB ports refuse to recognise the keyboard today.

  • by Ben Stanbury,

    Ben Stanbury Ben Stanbury Mar 13, 2014 5:25 AM in response to Prag mac´ tic
    Level 1 (0 points)
    Mar 13, 2014 5:25 AM in response to Prag mac´ tic

    I've been reading this thread today after experiencing the same problem with my MBP Retina, Cinema Display and USB numeric keyboard.

     

    I just wanted to add that I have just found a USB extension cable supplied with the Cinema Display in the house and this solves the problem for me also.

     

    Crazy. Nice of Apple to supply the solution to the problem in the first instance too :-/

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