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Lion Upgrade: No audio via miniDisplayport to HDMI (iMac)

Using the mid 2011 iMac and a (Denon1912) A/V-Receiver. iMac connected via miniDisplayport-to-HDMI-adapter to the receiver.


With Snow Leopard it worked. Video and Audio were always detected by the receiver and sent to the monitors/speakers.


With Lion the video-output of the iMac only gets activated when i put the computer to sleep and wake it up. The audio-output via miniDisplayport/HDMI does not work. The audio-options do not list my receiver - only the internal speakers.


Cables are connected on startup, A/V-Receiver is turned on and set to the correct channels before booting the iMac.


How can I fix this? Downgrade and wait for bugfixes?

iMac, Mac OS X (10.7)

Posted on Jul 21, 2011 2:40 AM

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Posted on Jul 21, 2011 6:49 AM

If you left all the peripherals connected while performing the Lion upgrade that may have confused the SMC. Do a SMC reset (it may take 2-3 attempts) and see if that helps. Please follow the instructions carefully.


SMC RESET

  • Shut down the computer.
  • Unplug the computer's power cord and all peripherals.
  • Press and hold the power button for 5 seconds.
  • Release the power button.
  • Attach the computers power cable.
  • Press the power button to turn on the computer.


PRAM RESET


  • Shut down the computer.
  • Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
  • Turn on the computer.
  • Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
  • Hold the keys down until the computer restarts and you hear the startup sound for the second time.
  • Release the keys.
94 replies
Question marked as Best reply

Jul 21, 2011 6:49 AM in response to Kahlzopf

If you left all the peripherals connected while performing the Lion upgrade that may have confused the SMC. Do a SMC reset (it may take 2-3 attempts) and see if that helps. Please follow the instructions carefully.


SMC RESET

  • Shut down the computer.
  • Unplug the computer's power cord and all peripherals.
  • Press and hold the power button for 5 seconds.
  • Release the power button.
  • Attach the computers power cable.
  • Press the power button to turn on the computer.


PRAM RESET


  • Shut down the computer.
  • Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
  • Turn on the computer.
  • Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
  • Hold the keys down until the computer restarts and you hear the startup sound for the second time.
  • Release the keys.

Jul 22, 2011 5:58 AM in response to Kahlzopf

On my MacBook Pro Early 2011 the sound is also not working anymore since Lion.


I have got a Displayport to HDMI converter and it is hooked up to my TV.

In Snow Leopard I always had sound on my TV with this cable, but since I have updated to Lion it isn't working anymore.


If I'm looking at the System Prefs -> Audio I don't see HDMI in that list no more.


I have reset the SMC and PRAM a couple of times, but it didn't brought me any solution! What now?


@ Topic Starter,

Dolby Digital 5.1 has worked for me through the HDMI in Snow Leopard, I haven't tested DTS, because my TV doesn't support it!

Jul 23, 2011 2:18 AM in response to rkaufmann87

For Drownd100 and myself on newer MBPs, resetting SMC is different (found this article http://support.apple.com/kb/ht3964) where the procedure is:


Resetting the SMC on portables with a battery you should not remove on your own


Note: Portable computers that have a battery you should not remove on your own include MacBook Pro (Early 2009) and later, all models of MacBook Air, and MacBook (Late 2009).


  1. Shut down the computer.
  2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
  3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
  4. Release all the keys and the power button at the same time.
  5. Press the power button to turn on the computer.
    Note
    : The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.


However, I *have* tried this and even so, still have not found it to work. Hopefully Drownd100 has more luck. Have made an appointment with an Apple Genius to get the official word, will update here later.

Lion Upgrade: No audio via miniDisplayport to HDMI (iMac)

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