Apple Event: May 7th at 7 am PT

Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Level 1

0 points

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

Best reply

rkaufmann87

Level 10

140,682 points

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.

View in context

94 replies

nycbmp

Level 1

0 points

Jul 11, 2012 4:23 PM in response to Kahlzopf

I have a setup which I know works (TV, receiver, HDMI cable, min-HDMI converter) because it all works just fine on my Macbook Pro. Now when I tried to connect to my imac (mid 2010 so I know it should work from a hardware POV), it doesn't. The video works fine, the audio is absent. I followed the instructions regarding the audiomidi frequency adjustment, and when I switch the settings it works for a brief second and then reverts to silence. Any ideas what might be causing that? At the very least I know the hardware is connected and operating probably, but somehow it seems something is being tripped at the software level. THANK YOU!

Adam F

Level 3

612 points

Jul 11, 2012 4:45 PM in response to nycbmp

The problem I had was going from the minidisplay port to mini-hdmi. It was solved by getting an adapter that carries audio out. No extra expense. I think I got bought on Monoprice. Under Leopard Snow, the previous setup on the same machine (2010 MBP 13") had worked fine - that was minidisplay port to DVI cable to HDMI adapter. Something under Lion doesn't allow the audio to go through. Hope this helps, NYCbmp!🙂

nycbmp

Level 1

0 points

Jul 11, 2012 9:00 PM in response to Adam F

Thanks Adam! Actually I have that mini-hdmi adapter. And I'm not running Lion on either machine. But what I did realize is that it's a mini port on the imac, but it's a thunderbolt on the mac book pro. I'm not sure if that's the issue (i.e. that the monoprice adapter I have carries audio from the thunderbolt port but not the mini port).

The imac sees the adapter, and allows the option of sending audio out, but it never arrives at the tv. Which is odd, since as I mentioned, when I go into the midi settings and make the changes per other posts, the sound comes out for 2 seconds before it dies.

duaneiac

Level 1

0 points

Aug 4, 2012 7:31 AM in response to Kahlzopf

This worked for me. Im on mountain lion

http://store.moshimonde.com/faq-minidisplayport-to-hdmi

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