[Macworld]

Post your comments for Repairing the mysteriously muted Mac here

[mariorelvas]

Hi guys, I belive this is the same old (2006?) problem. Check these images

http://www.google.co...iw=1267&bih=618

Best regards,
Mário

[mariorelvas]

some images

http://farm6.static...._8a04aa9169.jpg

http://www.redstarit...led-macbook.jpg

Mário

[Strawtag]

Yep, unless somebody started up with the shift key down after reading other helpful hints, then forgot.

[Subrunner7Mac]

I've got a 2 month old iMac 27". Suddenly the left audio channel does not play out of my head set (standard ear pods that come with iPhone 4s). I tried another headset (older iPod set) and a creative lab external speaker set plugged into the headphone jack. Left channel fails to play.
Both channels play out of the internal speakers normally when the headphone jack has nothing plugged into it.
Any thoughts?

[lasergm]

My MB Pro sound output quit several times when the outside temp was 41 C, indoor temp perhaps higher and I was busy on video Skype. I presumed it was the heat that stopped the sound card as it worked again after turning off the computer and letting it cool. But perhaps it was resetting the output.
Has anyone else had a heat related sound problem?

[richsadams]

I've experienced this issue on my '08 iMac since it was new...many others have as well...on old and new iMacs, MacBooks, etc. There are several threads on about it on Apple's forum - here's one:

https://discussions....tart=0&tstart=0

FIX: Similar to the suggestion in the article, unplugging the speaker cable from the Mac's headphone jack and plugging it back has always worked but it only takes 1x for it to work (for me).

One of the "fun" outcomes is that when I disconnect the cable from the jack there's a flood of "backed up" sound effects that play all at once!

[richsadams]

Quote

I've got a 2 month old iMac 27". Suddenly the left audio channel does not play out of my head set (standard ear pods that come with iPhone 4s). I tried another headset (older iPod set) and a creative lab external speaker set plugged into the headphone jack. Left channel fails to play. Both channels play out of the internal speakers normally when the headphone jack has nothing plugged into it. Any thoughts?

Try resetting the PRAM and NVRAM:

http://support.apple.com/kb/ht1379

Failing that, take it to an Apple Genius Bar or Apple authorized repair facility nearby. The one-year warranty (or three-year warranty if you bought Apple Care) is still in effect, it's a no-cost repair. If nothing is nearby, call Apple Support:

http://support.apple.com/kb/HE57

[richsadams]

Quote

I've got a 2 month old iMac 27". Suddenly the left audio channel does not play out of my head set (standard ear pods that come with iPhone 4s). I tried another headset (older iPod set) and a creative lab external speaker set plugged into the headphone jack. Left channel fails to play. Both channels play out of the internal speakers normally when the headphone jack has nothing plugged into it. Any thoughts? Try resetting the PRAM and NVRAM: http://support.apple.com/kb/ht1379 Failing that, take it to an Apple Genius Bar or Apple authorized repair facility nearby. The one-year warranty (or three-year warranty if you bought Apple Care) is still in effect, it's a no-cost repair. If nothing is nearby, call Apple Support: http://support.apple.com/kb/HE57

Apologies, meant to say PRAM/NVRAM and SMC!

http://support.apple.com/kb/ht3964

http://support.apple.com/kb/ht1379

[Subrunner7Mac]

I appreciate your comments. The fix was embarrassingly simple. The balance was set to the far right in the sound system setting for headphones. I had checked this earlier but at the time the headphones were not plugged in and I was seeing center balance for internal speakers. I'm not at all aware of how the balance was set so far off on headset since I did not make any adjustments to it to my recollection.
I got great help, although embarrassing from Apple Care.
Thanks to all who took the time to recommend solutions.