No Sound

I have owned a MacBook for over a year. With my MacBook, I have always used a set of fairly cheap noise-canceling headphones. One day, after plugging them in and after I began to play a song, I noticed that audio was only coming out of the right ear speaker.

Conceding that it must be because the headphones I owned were cheap and because I had stepped on them too many times, I discarded them and purchased a brand new top-of-the-line noise-canceling headset. After plugging it in and playing a song, I noticed that, this time, audio was only coming out of the left ear speaker. Thus, there must be an issue with my MacBook.

Help!

P.S. In the Sound page of System Preferences, the volume is turned all the way up. That is not the issue.

If sound is playing OK through both of the MacBook speakers (headphones not plugged in) then it's probably due to a loose or possibly internally bent (misaligned) headphone jack. Try gently wiggling the headphone plug after inserting it in the jack to see if sound returns to both sides. Or, try pulling the headphone plug slightly out of the jack to see if the sound returns. Not much you can do to repair it since the machine has to be disassembled to get at the jack.

Sometimes you can align the internal clips of the jack again by using a very small tweezers or a narrow hook type pin. Even if you can get the jack working, it's usually not long before the same thing happens again. Is your MacBook still under warranty or Apple care?

Regards.