Sound disabled upon restarting on 21.5" running 10.7.3

Discussion in 'Mac OS X Lion (10.7)' started by M3G4, Mar 21, 2012.

  1. M3G4 macrumors regular

    Joined:
    May 4, 2007
    Location:
    Kent, UK
    #1
    Hi all,

    I was wondering if anyone knows of a fix for my iMac 21.5" which seems to disable the onboard sound upon restarting?

    I understand that this can be remedied by resetting the SMC but I cannot be expected to do this each and every time the machine is restarted. Is there any way I can get it to work permanently?

    Upon restarting the volume icon is greyed out, and pressing the volume up/down keys bring up the volume box with a "no entry" sign underneath the icon. I've tried unplugging and replugging the external speakers to no avail, and this occurs with the internal speakers also. I've checked the correct device is selected in the volume settings and the optical output is not switched on.

    Lion really is a sack of ****, isn't it?
     
  2. TheAppleSource macrumors regular

    TheAppleSource

    Joined:
    Mar 9, 2012
    Location:
    United Kingdom
    #2
    Are you saying that you've tried resetting the SMC and then it works fine until you reboot? If so, I can't personally think of a reason as to why that would be happening. Typically an SMC reset would fix it "permanently" (within reason - definitely not just until you reboot again).
     
  3. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #3
    Actually, it's resetting the NVRAM that usually addresses volume issues.
     
  4. TheAppleSource macrumors regular

    TheAppleSource

    Joined:
    Mar 9, 2012
    Location:
    United Kingdom
    #4
    Indeed it is, my mistake. Thanks for the correction!
     
  5. M3G4 thread starter macrumors regular

    Joined:
    May 4, 2007
    Location:
    Kent, UK
    #5
    Either way - is this a problem with my machine or the OS? It only started happening after installing 10.7.3.

    Pretty sure resetting the SMC (unplugging, holding for 10 secs, plugging back in etc) was what fixed it before.
     
  6. TheAppleSource macrumors regular

    TheAppleSource

    Joined:
    Mar 9, 2012
    Location:
    United Kingdom
    #6
    From the Apple site:

    Resetting the SMC:

    Shut down the computer.
    Unplug the computer's power cord.
    Wait fifteen seconds.
    Attach the computer's power cord.
    Wait five seconds, then press the power button to turn on the computer.


    Apple states on their site that the SMC is associated with problems relating to, but not restricted to:

    Fans
    Lights
    Power
    System Performance
    Video

    So, from looking at that, it seems that the SMC shouldn't really be affecting your sound.

    However, as GGJstudios pointed out, the NVRAM is definitely sound-related,.

    Have you tried resetting the NVRAM/PRAM to see if that fixes the problem?

    Given that you said that the problem can be fixed and that it only started occurring after you updated to 10.7.3, I'm assuming it's an OS problem.
     
  7. GGJstudios macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #7
    The SMC doesn't relate to volume or speaker issues.

    Intel-based Macs: Resetting the System Management Controller (SMC)
    Mac OS X: What's stored in PRAM
     
  8. M3G4 thread starter macrumors regular

    Joined:
    May 4, 2007
    Location:
    Kent, UK
    #8
    Right, I just zapped the PRAM. Nothing - sound still out. Restarted, still no sound.

    Reset the SMC, the sound returned.
     
  9. TheAppleSource macrumors regular

    TheAppleSource

    Joined:
    Mar 9, 2012
    Location:
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    #9
    Hmmm, strange.

    To be honest, I'm not entirely sure what's going on then.

    Have you tried restarting without the external speakers plugged in?
     
  10. M3G4 thread starter macrumors regular

    Joined:
    May 4, 2007
    Location:
    Kent, UK
    #10
    Yeah, no luck unfortunately. Also tried replugging them whilst the system is on - still no luck =(
     
  11. TheAppleSource macrumors regular

    TheAppleSource

    Joined:
    Mar 9, 2012
    Location:
    United Kingdom
    #11
    Try what this guy suggests. Although I'm not sure if that's going to be the same for an iMac.

    Or try using the attached fix that someone on MacRumors has posted before (sorry, can't remember who it is).
     

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