I recently upgraded to Lion and now I can't connect to my TV with an HDMI cord. I need to be able to transfer webpages on my iMac on to a tv.

If i upgrade to mountain lion does anyone know if this will fix the issue? I know this HDMI thing is an actual problem, and many people are facing the same issue. I would rather not downgrade to snow leopard if I had to, I would like to upgrade to mountain lion if I knew that this would fix it.

So, my real question is if it is known that mountain lion fixes this issue or not?

  • I am not sure of the sure of the issue, but have you looked into AirPlay Mirroring? it comes build in with ML if you have a 2011 Mac, but AirParrot is an awesome alternative. I use that:-) Commented Aug 22, 2012 at 2:31
  • I suspect something else is wrong, nothing to do with Lion (tv settings or cable). So: Have you tried booting your SL backup (or even your SL Install DVD) to see if your TV can work as a display then? Commented Sep 26, 2012 at 19:22
  • I'm facing the same problem too. Once I changed to a new MacBook Air with Mountain Lion, I can't project to the TV using HDMI cable. It works fine on the same mini display port connected via VGA cable.
    – user174908
    Commented Nov 21, 2012 at 8:35

3 Answers 3


The operating system should not be an issue. As long as your television supports HDMI then you should be able to still use it as a monitor. Plug it in and go to

System Preferences-->Displays

and see if it shows up. If it doesn't, then perhaps something is wrong with the HDMI cable. You might also have your television on the wrong input. You need to switch to the corresponding input e.g. HDMI 1.

Either way, Mountain Lion will not fix your problem.


Could it be that you need to change your preferences to extend your desktop to the TV? Perhaps the upgrade reverted your settings? Sometimes the simplest answer is the right one.


I agree with Ace. This is likely caused by a different problem. FWIW, I'm successfully outputting from a 2010 iMac to my projector using a mini-DisplayPort to HDMI adapter, with Mountain lion.

Could you post a bit more info on the model of Mac you're using, the type of TV, etc?

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