TI 89 Help- some buttons don't work

[mikepolitz]

I've have been searching all over through TI 89 FAQs and troubleshooting websites but I couldn't find the answer to my problem with my calculator. I have the TI 89 Titanium. When my calculator is off, I can press the ON button to turn it on. However, once it is on the "2ND" button and the buttons in the row of the equal sign [ = ( ) , ÷ ] don't work. I have tried taking out the batteries and putting them back in. I also tried new batteries as well as resetting the calculator by pressing the diamond key, left, right, and ON button. However, none of these techniques seem to work. It is a fairly new calculator that has been kept in very good condition. Every other key seems to be working fine. If you have any suggestions as to help me fix this before finals that would be great! Thanks.