New, barely used 89 drains batteries quickly

Press left and right arrow and 2nd keys simultaneosly, hold it and then press ON. Release all keys at the same time and you will reset TI 89 Titanium.
Or, type diamond key simultaneosly with + or -
(plus or minus) key to resolve dark screen.

Having gone over a month without a response, I assume my suggested reset solved the problem.

Given a month without a response, I assume my suggestion worked.

A hard reset will clear all memory and should give you back control of the calculator.

1. Put the batteries in the calculator.

2. Press and hold left arrow, right arrow, and 2nd keys.

3. Press and release ON.

Here is what you do:

1) Press the Mode button.
2) Scroll down the list that appears until you find "Exact/Approx".
3) Change the setting for "Exact/Approx" to Exact.
4) Press enter to save the settings change.

You have three possible settings for "Exact/Approx":
1) Auto - The calculator will try to determine the best format.
2) Exact - The calculator will always give the answer in fraction form.
3) Approximate - The calculator will always give the answer in decimal form.

Hello,
After the change of batteries, the screen reverted to default contrast. You should try to darken the screen.
Press and hold the [Diamond] key and tap the [+] key. Keep at it until screen is dark enough.
Hope it helps.

Hello,
When you turn the machine down, it rests where you left it, in the state you left it: In case you wanted to continue with the same program, what you have already accomplished will not be lost.

After you turn it on, Press [2nd][QUIT] or just press the [HOME] button, and it will take you home.

Hope it helps

Hello,
The draining of batteries depends on usage. Turn calculator off when not in use. Use rechargeable batteries: Have two sets of them and change batteries before the ones in use are not fully discharged.
If you get tired of that, I suggest you have the calculator repaired.

Hope it helps.

1) Update the OS from the TI site.
2) check if button is sticking(not necessarily just the plastic button, but what it hits on the inside... you can clean the contacts on the inside of the calc with a Q-tip and rubbing alcohol.)

I don't have much experience with this specific calculator but those are my best bets.

good luck
-Saik0Shinigami

Mine did the same thing and I was told by Texas Instruments that I can send it in for repair--for $81 since it is more than 1 year old.