headphone jack is only emitting right sound.

go to system preferences > sound > Output and set it up like this.

Be sure that the headphone connector is pushed in completely. Be sure that the balance control is adjusted correctly.

You'll also have to use logical deduction first 🙂

1. Check with other headphones or other cable first.
2. Check with another application and/or file, to make sure it's not just the movie/music you'retrying to play that has audio in one side.
3. Go to application/utilities and open "Audio Midi Setup" to see if you have access to the balance controls on your soundcard (this varies from mac to mac) one side may be set to "mute".

if none of these things have worked, your output socket is probably damaged and you'll need to get it repaired.

Yes in some/most macs and depending on OS version you'll have this option. If not, I stillr ecommend trying other headphones, another file, and checking if left or right channel is muted.

Hi there,

i have the exact same problem...audio coming out of Right Headphone socket only. The Left Ear is dead.

At the time i was listening to music on my headphones when the Left side dropped out, the balance settings are fine and Audio Midi set up is correct. The speakers work fine.

I took it into an Apple Genius to confirm my suspicion that the internal Headphone driver had died on the Leftside, and after many tests my assertions were correct that this was a hardware problem - which is BS because my MBP is only 14 months old.

I also ran a test with the internal 'white noise' test for individual o/p (i.e left only ear and right only ear) and can hear Peak digital distortion at a very low level coming from the Left Headphone socket. This made me think that a capacitor has crapped itself.

Mac you suck big time as this is a recurring problem for your product for the last 6 years looking at other forums on the net.

Thank you so much. The balance for output of the headphone jack somehow randomly changed and I was able to figure this out and correct it because of your post. So once again, thank you!

Ha, I work in audio, and i forgot about checking audio midi setup. Thanks! I somehow adjusted a left/right balance and forgot about it!

Thanks Hefster,

I was convinced the newly discovered problem of attenuation on my right headphone channel was due to a hardware fault.

I tested the headphones on different devices; different headphones in same device; built in loudspeaker output; different audio files and playback of various audio; output via a Firewire audio interface; output via a USB audio interface.

I was getting ready to book a visit to my local Genius Bar when I came across this discussion thread via a Google link. Thanks to the Hefster I checked the bleedin' obvious.

To do the same first plug in headphones to the headphone port then launch Utilities and follow this longish path:

\Audio MIDI Setup\Built-in Output\Output tab\Configure Speakers\Stereo

Then run the white noise test by clicking on the left and right channels in turn. Do this even if the display shows the same output level for each channel. Next adjust both channels to the same level if they are now out of sync and click Apply\Done. If the channels are still in sync just click Done.

After clicking Done you'll be back at the main input/output window. Adjust the levels if they are out of sync (which mine were when I got to this stage even though everything had looked normal in the displays up til then).

This solved the problem for me but if you have tried the various checks I listed above and the Utility test as described then the problem is most likely hardware although it could be a software bug.

I don't know what caused my right channel to attenuate in the first place.

K

Message was edited by: Audiodrome

I am SO thankful you replied. I really needed this to work right now. It worked! I have no idea how one ear got set to mute, but it's fixed now!
THANK YOU!

Make sure you have your headphones plugged in when you check the balance settings.

Similar problem and thought I would need to go into the Genius Bar and pray for warranty coverage. I had checked the Sound settings in the System Preferences the other day and it looked like everything was balanced properly. However, after reading this thread, I plugged in my headphones and checked Sound in System Preferences again -- guess what? With the headphones plugged in, there was a new profile on the Sound screen and the balance there was skewed.

Not sure how it got that way, but the problem is corrected and the sound is wonderful.

Do you think this is something that would persist across OSes? Does this set something on the virtualized bios?

I'm running Windows 8 and have had no problems with the headphone jack up until today. Today, however, only the left channel is working and the right channel is VERY VERY faint (just as Kaihoe mentioned above).

I haven't booted into OSX in over a week, so I know I've changed nothing as far as that's concerned (nor could it have been changed by OSX)

My sound settings (in Windows) show the balance set correctly.

Incidentally, last night I left the PC on overnight and drained the battery (wouldn't even turn on this morning without power, which is odd since it auto-shuts down with 10% left).

One thing that has always 'worried' me is that when I plug in my headphones, Windows detects as a new device (plays the sound as if I plugged in a USB drive). This always seemed awefully doofy to me - I'ver never had a piece of computing hardware treat a pair of headphones like a new device. I'm not familiar enough with Apple's virtualized bios, what other hardware might be virtualized, or anything else Apple-specific that could be causing this .. other than simply poor hardware quality control or the as-expected-from-Apple poor software/driver quality.

I'm a very technical user and engineer/developer. As much as it makes zero sense to me that I should have to boot into OSX to change a software setting to fix what appears to be a hardware problem, I'll give it a shot

Does anyone have any better ideas? (****, are there any forums 'official' Apple reps respond on?)

Rebooting windows multiple times had no effect.

When I rebooted into OSX, the right channel worked. I did not have to change any settings.

I rebooted into Windows and everything was back to normal.

I was going to follow AudioDrome's instructions but realized that there is no 'balance' to adjust - you can only adjust the channel to output the selected channel (if that makes sense .. the former is 'Left' vs 'Right' while the latter is '1' vs '2').

My theory is that the main (and only?) battery drained and that's what is used to maintain the virtualized bios/hardware state. My system clock was also reset (but the date was correct?!?).

Aparently this can happen to any macbook pro that has been connected to a projector using a thunderbolt cable, its crap really but it only happens with the dodhy VGA cables and not the apple made ones

Same thing over here today... doh.... 😊

SparkyCanada

Perfect that did it for me! Really have no idea how it changed in the first place though.