iPhone 5, 6.1.2 jb

I've got some heating problems and the headphone jack suddenly does not work. Was working yesterday just fine, suddenly today, it doesn't. Did all the tricks, swabbed out the jack port with a Q-Tip, canned air, powered off and restarted, put the earbud jack in and out several times, etc. Nothing works. Now I read to try Reset All Settings. If I do that, will it break the jb?

Also, since this is a hardware issue, and still under the 1 year warranty, what are your experiences that an Apple Store will fix it? I remember last year (or two?) I took in my jb iPod Touch 3G, it was obvious it was jbroken, it was for a hardware issue, and no problem, they replaced it for free.

I've read online that some people with this issue of the headphone jack not working, they insist on doing a restore at the Apple Store. From what I've read, if I want to keep my jb, I don't want them to do that, right?

At any rate, "Reset All Settings" on a jb, up or down?

Thanks!