No Sound From iMac Internal Speakers

I had this problem - it seemed to have happened when I was trying to figure out how to get an Ibook to upload - I tried a few things I found on the internet. Finally I got it to upload and then the sound disappeared - it took me a while to figure it out but it seems I had inadvertently switched the output sound to airplay on a different device -

Try this - go to perference and sound and make sure that the output sound to the internal speakers

Thanks for your post. The imac headphone jack also created a problem for me after I had disconnected my external speakers to hear what the playback for a recording I had just completed sounded like on the internal speakers only. There was a crackling sound from my external speakers as I removed the mini stereo plug from the head-phone socket and the volume icon greyed out on the monitor and was non-responsive. Not even a re-boot with all cables removed from the imac and checking that everything was okay in the sound preferences window would get the volume icon working again. There was no red light shining from the head-phone jack, so after reading your post, I again re-inserted the exterior speaker's male stereo plug all the way back into the head-phone socket and slowly turned the plug and gently wiggled it about and the volume icon returned to black and was working again with external speakers engaged. I gently pulled back on the mini jack plug just enough to disengage the connection and the internal speakers began to operate.

I suspect that the imac headphone socket may be a hair's breadth size too large for a conventional or generic type of stereo mini jack which creates a dodgy connection and the imac's defence is to shut down it's sound driver. Perhaps too, one should consider powering off the external speakers before removing the stereo jack from the imac headphone socket and when re-inserting.

Does anyone know if Apple sells a male to female mini stereo cable specifically designed for the imac head-phone socket?

Have you tried turning up the volume and please describe the exact process you did to reset the PRAM and SMC, please do not skip a step. Also check to see if anything is plugged into the audio connectors in the back.

There are multiple methods for resetting the SMC based on the type of Mac you have. Please describe the steps you took for your iMac, they are totally different than those of say a MacBook or MacBook Air.

Try resetting it with all the peripherals unplugged. Leave them unplugged and then retry the sound. If that doesn't work create a new user account (call it TEST ACCOUNT), log into it and see if you have the same issue. If it disappears you know it's a software issue in your normal user account and not global.

If its any use to anybody I had this exact same issue with no sound. I googled and tried everything suggested to no avail so booked a Genius appointment.

I then remembered I had been trying to get the Dictation tool to work so I could dictate into the word processor instead of typing. So I went to Dictation and Speech and simply turned off dictation and the sound came back on! I hope it helps some of you.

me too !!no sound

I had this problem a while back, but it went away before I could work it out. It happened again today and I now believe it is a transient hardware issue in the headphone jack (possibly related to temperature/humidity/dust). The system seemed to get confused and think it was using digital audio out when it wasn't, and plugging in my headphones in a few times and twisting the jack a little seemed to make it the problem go away.

Similar description: http://forums.macrumors.com/showthread.php?t=1155397

Thanks ObiJuan2080!!!

I just ran into the same problem as you. Nothing plugged into my iMac except power, kbd and mouse and for some reason I had no sound. Pressing volume up/down keys on the keyboard wouldn't do anything but show the "not permitted" circle with slash through it like the image in your original post.

I killed coreaudiod and after it restarted (automatically from launchd I presume) the sound was working fine!

A reboot might have fixed it, but killing coreaudiod was a lot quicker...😉

Cheers,

Dean

I had this same issue...my iMac's sound just mysteriously stopped working. I went into System Preferences>Sound>Internal Speakers ....checked the mute button and then unchecked it and the sound magically came back....not sure what the deal was but it's working now. 🙂