5 Replies Latest reply: Dec 17, 2012 1:06 AM by LobsterMan
LobsterMan Level 1 (0 points)

Weird issue with a fireinds iMac I'm trying to sort out. 17" iMac Late 2006, Running OS X Lion


No sound once the system is loaded. The system doesn't see built in audio in or out. Headsets don't work either.


Built in audio doesn't show both in system preferences and system profiler, as if it doesn't exist.


I do get a startup chime, so this is obviously software related and not hardware related.


Here's what I did, with no avail:


1. Reparied Permissions

2. Reset PRAM

3. Reset SMC (or at least I think I did)

4. Reinstalled OSX

5. Opened and quit garageband (read that somewhere)


Any other suggestions?

  • den.thed Level 7 (26,017 points)

    In the area of software, go to Applications > Utilities Audio MIDI Setup and check to see what's up with the Built-In audio settings.


    Screen Shot 2012-12-16 at 9.14.17 PM.jpg


    Also be aware that startup chime is set to play thru the internal speakers and then when the software is loaded and the Audio MIDI Setup kicks in, it switches the Audio to the output port if something is plugged into the port.




    In the area of Hardware, it may just have a stuck micro switch in the Audio Output Port. Try plugging in a set of iPod buds or Headphones and see if you have sound output thru them.


    If so, then the micro switch inside the output port may just be gummed up and stuck. To clean and attempt to unstick it, disconnect everything including the power and spray a very very very small shot of Electronic's cleaner into the port and work a jack plug in and out a few times.


    Be sure to wait for a few minutes for the electronic's cleaner to fully evaporate before powering up the iMac and then check to see if both the internal speakers and output with buds or headphones is working correctly.


    If not then who knows, it could be anything from a damaged audio card to a bad logic board where the jack ports connect onto it.

  • LobsterMan Level 1 (0 points)

    Built in input and output don't show there either. No sound from earphones/line out either.


    The working startup chime is convincing me not to give up, because at it's most basic level, the computer knows how to output sound.

  • den.thed Level 7 (26,017 points)

    Is it booted in Safe Mode? Audio input or output devices are disabled in Safe Mode.


    see > Mac OS X: What is Safe Boot, Safe Mode?


    Try starting up without or using a different keyboard in case the Shift Key is stuck on the one he has.


    I'd also create and test a new User Account, in case the Account is corrupt or has some bad third party audio software.

  • LobsterMan Level 1 (0 points)

    It's not in safe mode, and no sound in new accounts.


    I think I've possibly found the problem: The idiot messed with some kernel extensions, and the Lion installer apparently carries them over when you reinstall. I removed all the kernel extensions and reinstalling. Hopefully this resinstall will be "clean" enough

  • LobsterMan Level 1 (0 points)

    Yes, that solved that. I wish there was a way to customize the lion install.