I haven't used my TI-83 Plus in a few years and now i need it. I changed the batteries and tried to turn it on. It won't turn on. I'm thinking maybe I need to change the back-up battery?
Office Equipment & Supplies - Texas Instruments - TI-83 Plus Calculator
Answers & Comments
The backup battery is only to retain the contents of memory while you change the main batteries. It does not affect the operation of the calculator in any other way.
TI calculators have an annoying habit of dimming the screen when the batteries are changed so that it appears as if the calculator isn't turning on. Turn the calculator on (or at least press the ON key). Press and release the 2ND key. Press and hold the Up-arrow key for a few seconds and see whether the screen becomes legible.
If this doesn't do it, please reply to this post and we can go on from there.