Audio Problems on Samsung Tablet

No matter what headphones or ear buds I use, the sound on my Samsung Galaxy Tab 3 only comes out of the left side. It comes out of both the speakers when I'm not using headphones or earbuds. This is the case on every app I've tried.
I've tried adjusting the sound ratio in the settings, to no avail. The sound just gets quieter.
The whole for plugging in the headphones doesn't appear to be damaged in any way.

Help please.

Even though there may appear to be no physical damage to the headphone jack, there could be some internal damage such as a bad wire somewhere inside of the tablet itself.

I will ask this: have you at least tried to wiggle your cables around to see if it could fix anything?

Yes, I have. However I do not have the proper means or experience to examine the interior.