Yosemite broke my HDMI

Discussion in 'OS X Yosemite (10.10)' started by inflame93, Jun 4, 2014.

  1. inflame93 macrumors newbie

    Jun 3, 2014
    Hey guys,

    Did anyone else have any dramas with their HDMI after a yosemite install?

    Downgraded to 10.9 but still no dice
    Also cleared the window server prefs and PRAM

    So… calling all mac nerds! Any ideas on how to fix?
  2. iMacBooked macrumors 6502a


    Jul 19, 2013
    4 8 15 16 23 42 ✈ Country: Belgium
    I don't know if it could be of any help, but when I had this problem, I just rebooted with the HDMI-cable inserted, and it solved my issues. Settings or PRAM reset didn't work either, but this easy thing worked lol.
  3. inflame93 thread starter macrumors newbie

    Jun 3, 2014

    Thanks bud, will give it a shot... Hopefully that does the trick!
  4. inflame93, Jun 5, 2014
    Last edited by a moderator: Jun 5, 2014

    inflame93 thread starter macrumors newbie

    Jun 3, 2014
    Ok, lets settle a couple things here.

    1. I am a active apple developer (more-so UX design, but thats irrelevant) - My software was downloaded legally, for the purpose of testing apps, through the apple developer dashboard. Yes, I agreed to the updates terms and the PLA, blah blah blah.

    2. My originally post clearly showed that I tried multiple fixes other than what the average tech person would know to do. If you werent so quick to jump on the flame bandwagon, you'd see that the first line of my post was:​

    Sorry, maybe my average joe mind isn't as smart as you, but is that not what you said you expect a developer would say? ask for corroboration? Asking if anyone knows a fix isn't as big a deal as you think it is.

    Sounds like you had a bad day on your help-desk with some inexperienced people and are taking it out on others. Should I suggest maybe Ashtanga Yoga? Either that or you need a drink. Peace x
  5. maflynn Moderator


    Staff Member

    May 3, 2009
    [MOD NOTE]
    Posts were removed because they were off topic and derailing the thread. Please stay on topic. If you cannot help or do not wish to help the OP, then move on.
  6. CyBeRino macrumors 6502a

    Jun 18, 2011
    Tried an SMC reset yet?
  7. inflame93 thread starter macrumors newbie

    Jun 3, 2014
    Thanks for your reply! Yep, I thought that might do the trick because it controls some of the video controller settings.. unfortunately no such luck.

    The bug came up from having my display connected by HDMI during the setup process - the whole setup was in widescreen non-retina mode, and it looks like that locked the setting to mirroring rather than extend display. For some reason my 2nd screen doesn't like mirroring.

    Going to do a clean install today, need it working for client presentations :mad:
  8. Astroboy907 macrumors 65816


    May 6, 2012
    Spaceball One
    SMC bypass? (Different than reset, though you would likely know that). Not sure how to do it on a retina though. Usually its hold the power button for 10 seconds with the magsafe connected, disconnect the magsafe and hold it for another 10 seconds, and then plug in the magsafe and hit the power button. Behold, the fans run at full speed and it boots. Then it usually takes a restart to get everything back to normal.

    Usually this does the trick when an SMC rest seems to get stuck on new hardware or some such.
  9. thinkyhead, Nov 18, 2014
    Last edited: Nov 18, 2014

    thinkyhead macrumors newbie

    Dec 4, 2011
    I'm still looking

    I just got the 10.10.1 update and it didn't fix the issue for me. But if I reboot my laptop into Mavericks the HDMI screen works fine! I would love to find some solution that works. This is really annoying and the first time in history that I have wanted to downgrade OSX.

    Edit: Oops, spoke too soon. Now it won't show up when using 10.9 either. So I'm in the same boat. I've tried some other proposed solutions (e.g., deleting com.apple.windowserver* and com.preference.displays* files from /Library/Preferences and ~/Library/Preferences/ByHost, reboot and reset PRAM...) but nothing has worked yet. Now I have to find some way to make sure the cable is still good.

    Edit 2: I just tried a Mini DisplayPort -> VGA connector and that works fine, so I guess I'll stick with that for a while. I will have to try some other brand of MDP -> HDMI cable and see if it works also.
  10. richszabo macrumors newbie

    Jan 2, 2015
    Install Thunderbolt Firmware update 1.2 to to fix this

    Install Thunderbolt Firmware update version 1.2 to to fix this. Worked for me.

  11. iPhonePunker macrumors newbie

    Nov 22, 2012
    same issue

    yea I have the same issue but I'm using a EVGA GTX 980 SC i tried the thunderbolt firmware update but it told me that my machine did not need it and closed the installer. I'm currently using Mac Pro 1.1 with 10.10.1 installed with SFOTT and i had x2 EVGA GTX660s SC installed in it and had no issues with HDMI support. only the DVI and 3 display ports are working but when I use windows 8.1 in bootcamp the HDMI works great even when it comes to upscaling to 4K is there a kext that could be modified in anyway kinda just spit balling here ;)

    My Mac Pro 1.1 Spec's : x2 intel Xeon x5355, 16GB Kingston FM RAM, 120GB PNY SSD,1TB WD black Enterprise HDD,900W power-supply,EVGA GTX 980 SC

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