iMac Volume Control Greyed Out

[dmw16]

I have a 27" i5 iMac and I've noticed recently that my volume control is greyed out. I can't adjust the volume with the slider or the keyboard and the speaker icon (and the screen notifications are greyed out).

When I plug in headphones they work fine, but when I remove them the icon reverts back to grey.

Any ideas?

EDIT: Plugging in headphones then removing them seems to fix it if I leave the headphones in for a little bit first.

 

[ChAoTiCpInOy]

Might be something is making the iMac think that an optical cable is plugged in. Check your audio settings.

 

[Adramalech]

I have a 27" i5 iMac and I've noticed recently that my volume control is greyed out. I can't adjust the volume with the slider or the keyboard and the speaker icon (and the screen notifications are greyed out).

When I plug in headphones they work fine, but when I remove them the icon reverts back to grey.

Any ideas?

EDIT: Plugging in headphones then removing them seems to fix it if I leave the headphones in for a little bit first.

If you have time, please create another user account and see if the same thing happens.

If it does, you might have a hardware issue. Just like was previously mentioned, the iMac more than likely thinks something is plugged into headphone jack and you plugging and unplugging a set of headphones fixes it temporarily. Did you have an Apple Store close by?

 

[dmw16]

Would it thinking I have something else plugged in cause it totally grey out the controls as opposed to just not causing the iMac internal speakers to put out audio?

I have an Apple store fairly close by but lugging my 27" iMac in is a fairly big task. Plus it isn't s problem I've yet been able to consistently replicate.

 

[Adramalech]

One more bizarre question, is there a red light that is coming on inside of the audio jack? (Optical Out possibly turning itself on.)

 

[dmw16]

One more bizarre question, is there a red light that is coming on inside of the audio jack? (Optical Out possibly turning itself on.)

Funny you say that because I swore I saw a red light coming out of jack but didn't think much of it. Now it isn't there, but the audio is also working.

 

[KeithP]

Might be something is making the iMac think that an optical cable is plugged in. Check your audio settings.

Agreed. Check the settings in Audio MIDI Setup.

-KeithP