TI-89 Titanium batteries Problem

[jksik92]

I use TI-89 Titanium normally.

It was not even a month since I changed my batteries.

One day I pressed on but did not turn on.

I tried out other batteries and found out that batteries were not the matter of problem.

What's wrong?

What should I do?

 

[Mark44]

Your calculator contains two kinds of batteries: the three AAA batteries that you changed not long ago, and a silver oxide backup battery. Your problem might be that the backup battery is dead. Here's some information from the user manual for your calculator - http://education.ti.com/downloads/guidebooks/graphing/89ti/TI89TitaniumGuidebook_Part2_EN.pdf

1. To replace the silver oxide backup battery, remove the battery cover and unscrew
   the tiny screw holding the BACK UP BATTERY cover in place.
2. Remove the old battery and install a new SR44SW or 303 battery, positive (+) side
   up. Replace the cover and the screw.