Previous 1 2 3 Next 36 Replies Latest reply: Jul 15, 2015 5:07 AM by davidhq Go to original post
  • Sudi11 Level 1 Level 1 (0 points)

    Same here. I had some issues in the evening so I turned my MBP off. After starting it in the morning the external display was not recognized any more. I've tried it with two monitors, with adapter and direct mini display cable, tried all of the suggestions listed above, but nothing. I'm very disappointed...

  • douglasfromedinburgh Level 1 Level 1 (0 points)

    Yes i'm having the same problem. One morning my second display was not detected. Tried all of the above and still nothing. Now have a monitor i can't use apple!!


    Ok now i've fixed this, the only way is to try connecting display to the other thunderbolt port. This fixed the issue. I hope both ports are still working but who knows?

  • andyvj Level 1 Level 1 (0 points)

    hi guys

    yes you guessed it i have problem with a dell u2713hm monitor and an iMac i5 2.66 ghz (late 2009 on 10.9.4)

    is their a work round for the iMac to detect the monitor

    ie cables and such

    all it see's is a "tv" in system information ..



  • quarkdoll Level 1 Level 1 (100 points)

    This problem is being discussed in many threads (for example 10.9.4 - Thunderbolt display for 6630M (Mini mid-2011) still broken and Second display problem with 10.9.4 ).


    You should file a bug via -- they'll close it as a duplicate, but this is our only recourse (and as it stands, they appear not to give a scheiß since this has been a problem for a couple releases now).


    You might have luck using an HDMI cable; i'm currently using that to do non-native resolution display on a Dell U3011.

  • andyvj Level 1 Level 1 (0 points)


    hi quarkdoll 

    could i go back as in software to resolve this problem ?

    as this seems to have arose in the past few software updates/releases..


  • andyvj Level 1 Level 1 (0 points)

    hi quarkdoll

    could i partition my hard drive and run.. say osx 10.7 on one side and run 10.9/10.10 on the other.. i will be using in traktor/ maschine 2 software plus logic 9 - x and maybe final cut 7



  • quarkdoll Level 1 Level 1 (100 points)

    Making sure you have all of your data backed up, you could do either of your suggestions (go back to an earlier version of 10.9, or partition the drive and have a 10.9 and not-10.9).


    In which ever situation, after backing up your data, you'd install the base operating system -- for example with the App Store Mavericks installer, that should produce 10.9; then instead of using the App Store to update, install the Combo update for the dot-version you wanted (for example the 10.9.2 to avoid picking up 10.9.3 / 10.9.4's ridiculous bugs -- OS X Mavericks 10.9.2 Update (Combo) ).

  • ThatTomHall Level 1 Level 1 (0 points)

    Having the same issues, and nothing works.  Sometimes plugging it in gets it to show at 10% brightness for a bit, then goes off. Mouse thinks the other screen is there, but it is just a dark screen.  Will file a bug report.

  • dunkmeister Level 1 Level 1 (0 points)


    I had this guy's problem exactly, and I want to share the EASY solution. Has to do w/ how in Mavericks they fiddled w/ (got rid of, sort of) the "detect displays" button. With the "Displays" Sys Prefs open, hold down OPTION. Then click the button. Mac should then recognize your ext display. What a relief. For more info, the article recommended by another user helped me:

  • zenthing Level 1 Level 1 (0 points)

    OK here's my story and here's my solution. I just got a fairly new mac mini i7 os 10.9.4 that is replacing my mini core 2 duo os 10.9.4. A Viewsonic monitor I hookup with DVI and a 42" toshiba with HDMI (using adaptor) as my alt / movie screen. When I installed the new mini I bought an adaptor cable (thunderbolt to hdmi) and used the HDMI out to the 42". When I started up the new mini would not recognize the the Viewsonic (DVI). Forum searches, cable plugging and unplugging all to no avail.  The thing I was noticing was that the thunderbolt would go to my HDMI Toshiba OK. So my workaround finally came some 4 hours later. Thunderbolt to HDMI (using an adapter). HDMI to DVI ( using an adaptor cable I had for my macbook pro). Nightmare Solved. Hope this helps someone else!!

  • Johann Beda Level 1 Level 1 (0 points)

    I have a Mavericks MacMini server circa 2012 (mini-displayport rather than thunderbolt) that I have been messing with and when swapping my monitor connection between that machine and my regular machine, once I unplugged the monitor from the MacMini I could not get the screen to be recognized again - plugging it back in it would stay black. With this discussion thread, I tried plugging in the DB->DVI adapter without the DVI cable to the monitor first, and then reattaching the cable and that worked. It seems as though this MacMini needs this adapter-to-monitor connection to be made in order to detect that it should send a signal through that port.


    Now if I can only track down the disk I/O errors...

  • quarkdoll Level 1 Level 1 (100 points)

    Just being a technical pedant -- on Mac Mini server from 2012: that is Thunderbolt [via Mini DisplayPort] (2011, as well).

  • Johann Beda Level 1 Level 1 (0 points)

    quarkdoll is correct that the 2012 is TB.


    I guess my memory is bad as to when this was purchased. It looks like this machine is a 2010 model:


    Model Name:    Mac mini

    Model Identifier:    Macmini4,1

    Processor Name:    Intel Core 2 Duo

    Processor Speed:    2.66 GHz


    It is mini-display-port with a monitor icon rather than a thunderbolt icon.

  • Iamshazam Level 1 Level 1 (0 points)

    Ok so I was having the same problem after installing 10.9.5 on my internal HD on my iMac 2010 - which I have been using Mountain Lion and 3 screens for years and no problem at all. What was more perplexing is that I had been running 10.9.5 off an external for months (backup system) with no problem and with DisplayLink and 2 external monitors. I tried uninstalling DisplayLink, fixing permissions, disconnecting and reconnecting the DVI monitor = nothing worked. The screen would come on for a second and then go black. Finally I swapped out the DVI adapter for a second one I had lying around and WOW, the screen is now working again!! Which is great cause I really didn't want to have to reinstall down to an earlier OS version. Hope this helps!!

  • masterudon Level 1 Level 1 (0 points)

    Mine stopped working all of a sudden today.. (HDMI DisplayPort to external monitor)

    Found a temporary solution though.


    I found out that it only doesn't detect external monitor if MagSafe was plugged in. Once it's running off battery, reconnect the HDMI cable - tada.


    Bug, perhaps?