Sound only from Headphones Output not speakers

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Level 1

43 points

Sound only from Headphones Output not speakers

I have an iMac 2.7GHz Inel Core i5 (Model iMac12,2) running iOS 10.7.4. The computer was installed about a year ago and came with 10.7.2 pre-installed. When I installed the computer, I attached my external speakers to the headphone output and everything worked well. Recently, I unplugged the headphone output and realized that I have no sound. I don't think I initially ever tried to run it without the external speakers

With the speakers plugged in, the Sound window in System Preferences works normally, and sound is fine. When I unplug the speakers, the sound ends and the Sound window switches to a notification that "The selected device has no output controls", the Output Volume slider jumps to the 100% position and is not selectable or moveable, and the mute switch is grayed out. At the same time, the volume in the menu bar becomes grayed out.

Does this sound like a hardware problem or is there some other software switch that I need to change elsewhere in the computer?

Thanks,

Dave

iMac, Mac OS X (10.7.2), 12 GB Ram

Posted on Jun 19, 2012 6:53 AM

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Answer 1

Jun 27, 2012 7:21 AM in response to PianomanDave

Dave, I have had this problem on my MacBook Pro for many months. I've tried EVERYTHING Apple suggested - SMC reset, PRAM reset, everything EXCEPT take it in to be serviced by Apple. Here is my solution, which overcomes the hardware failure caused by the headphone jack optical sensor thinking something is plugged in there when there isn't.

If you do not want to pay Apple to fix your MacBook optical sound jack hardware, you can overcome the problem with this procedure.

This fix re-routes the output sound to the headphone jack input, and then to the speakers.

Step 1. Plug headphones in (don’t worry, you won’t use them)

Step 2. Change System Preferences -> Sound -> Change Internal Speakers to an Input!
Step 3. Done!

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Answer 2

RRFS

Level 5

4,522 points

Jun 19, 2012 7:05 AM in response to PianomanDave

Two things, there is a contact inside the headphone jack that has to make up when there is nothing plugged in. If it doesn't then the system thinks something is there, even though there isn't. Plug and unplug a few times, rather sharply when unplugging but still being careful.

The other is a SMC Reset which has some effect on the sound system:

SMC RESET

http://support.apple.com/kb/HT3964

Shut down the computer.
Unplug the computer's power cord and ALL peripherals.
Wait 15 seconds.
Attach the computers power cable.
Wait another 5 seconds and press the power button to turn on the computer.
It is the 5 second timing that initiates the reset.

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