Happened to me, and sorry, no matter what you do, all the software resets in the world aren't going to help you
TI said I could mail them my calculator with a check for $70 and they would fix it, but I opted to just buy a new one.
Now depending on where you are in your education, I recommend a different new calculator for you.
If in high school still, and you haven't taken your ACT or SAT, then get either another TI-83+ or TI-83+ Silver Edition (which is just slightly faster than TI-83+ due to more ram) or the newer versions of these, the TI-84+ or TI-84+ Silver Edition (both of which are faster than all TI-83's, and the silver edition again has more ram thus slightly faster).
If in high school and have taken ]your ACT or SAT and are happy with your score (as in, you don't plan on taking them again), OR if you are in college now, you are free to go for any I have mentioned above. However, if you don't mind the challenge of learning how to use a similar calculator in a different manner, and/or if you're majoring in a science-related or engineering-related field, I would recommed the TI-89 (old one) or the newer (and better) TI-89 Titanium, which I purchased. With all it can do, it's a nice tool to have in college, but for the same reason, it's banned from the ACT and SAT tests.
Anyways, just check out the TI site and/or give TI a call/email, and see how much it would be to repair it (probably about the same as for me, which is why I figured buying a new calculator was better). Hope this helps! Best of luck.
TI site:
http://www.ti.com/