I'm trying to hook up my IMAC mini-DVI port to my Samsung HDTV. I have a (mini-DVI port to HDMI) adaptor plugged into a 15' HDMI cable. This plugs into the TV's (DVI/HDMI) port.

I also have a 15' audio cable plugged into the MAC's headphone port then to the TV's (PC/DVI) audio port. Nothing works, video or sound. TV says no signals detected. MAC doesn't know it's connected. Does anyone have the slightest idea as to what the problem is? Do I somehow have to activate the mini-DVI port?

2 Answers 2


Apparently older Macs don't support audio through HDMI. Audio needs to be transmitted separately through the jack connection on your Mac, just as if attaching speakers.

Then depending on your TV could be jack or RCA.


No, the iMac should auto-detect the external display when it is connected. I'd try, in order of presumed difficulty:

  • Make certain the correct input is selected on your display. The lack of audio makes me suspect there's an issue there.
  • Make sure your display is set to use the Line-in jacks instead of the HDMI audio stream.
  • Boot the iMac with the external display attached and the correct input selected.
  • Check your HDMI cable with another source (perhaps a DVD/Blu-Ray player) do make sure it is working.
  • Check your MiniDP-HDMI adapter on another mac (with the SAME HDMI cable and display, if possible.)
  • Try swapping-in a new MiniDP-HDMI adapter and HDMI cable.
  • Try a different external display.
  • Consider upgrading your OS X to a newer version (I've used external displays with 10.5, but it's not impossible for the HDMI adapter to need a newer/different driver.)
  • Take your iMac to the Genius Bar at your local Apple store and see if they can assist you.

As you start replacing hardware in the equation, feel free to revisit any of the prior steps in the process.

  • I don't have a line-in audio port only the PC/DVI audio port. I tried using a Sony TV and got audio with the MAC audio out port but no video. I did check out the HDMI cable and it's good. My other MAC is newer and doesn't have the DVI port. I also just received the update to Snow Leopard but haven
    – Bill K
    Feb 14, 2014 at 20:42
  • haven't had a chance to load it up. So excluding the upgrade, either the new mini-DVI to HDMI adapter is bad or the MAC isn't putting out a good DVi signal. Also possibly, could the TV not detect the audio at the PC/DVI audio input because it doesn't detect a DVI signal???
    – Bill K
    Feb 14, 2014 at 20:50

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