It is not turning on and I replaced the 4-AAA batteries and the 1616 watch battery

I can't see how a battery vent cap could take out your AC compressor.

Good morning, afternoon, evening or night; whatever time of day you are viewing this solution post. Thank you for choosing FixYa to assist you. You are having problems because you calculator won't turn on. I think you should try changing the batteries. Did you know that your calculator has two batteries powering it? Not only are the 4 AAA batteries powering it, but there is also a CR 3V Lithium Back Up battery powering it as well. First, try changing the 4 AAA batteries. If that still does not power your calculator properly, you will need to replace the lithium back up battery. You can find this at a department store or store that carries electronics. To do this, open your regular battery compartment. Above the AAA batteries is a compartment that says "BACK UP BATTERY CR1616 OR CR1620" with a picture of it. Use a small crosshead screwdriver to open the compartment. Take the old battery out and replace it with the new one. Rescrew the lithium battery compartment back on and close the AAA battery compartment. Turn on your calculator and see if that works. I hope this solution solves this.

I've had this issue before with my TI-83 Plus. I'm not sure exactly the solution I used, but these steps progress through the mildest to most extreme methods of fixing the calculator.

Solution 1: Take the batteries out.

Odds are you've tried this already, but it bears mentioning.

With the calculator on, remove the triple A batteries housed in the back. After a few seconds, replace them and turn the calculator on.

Solution 2: Clear the RAM.

Remove one of the AAA batteries. Press and hold the [CLEAR] key. While holding [CLEAR], reinsert the AAA battery and then turn the calculator on. The calculator should display the message "RAM Cleared". Release the [CLEAR] key and then press it one more time to remove the message.

Solution 3: Reinstall the operating system

Remove one of the AAA batteries. Press and hold the [DEL] key. While holding [DEL], reinsert the AAA battery and then turn the calculator on. The calculator should display "Waiting...Please install calculator software now"

Here is the website to reinstall your OS. First you'll need the TI-Connect software.

Solution 4: Remove all sources of power. This is a risky move, but if your calculator will absolutely not work after you try even reinstalling the operating system, it might be your last hope.

Remove all of the batteries including the round lithium battery for 5 minutes. After the 5 minute period, reinsert all of the batteries and turn the calculator on. Adjust the contrast if necessary.

Remove all four AAA batteries. Press and hold the ON key for ten seconds. Replace the batteries. Turn the calculator on (you may have to adjust the screen contrast again).

If this doesn't do it, please add a comment to this post and we'll go on from there.

The following are 4 different things you can try that is on the Texas Instruments Website: " 1. Try a new set of AAA batteries. 2. Adjust the contrast by pressing and releasing the [2nd] key followed by pressing and releasing the up arrow; repeat as necessary. To adjust or lighten the display, use the down arrow. 3. Remove one of the AAA batteries. Press and hold the [ON] key for 20 seconds. Reinsert the AAA battery and then turn the calculator on. 4. Remove all of the batteries including the round lithium battery for 5 minutes. After the 5 minute period, reinsert all of the batteries and turn the calculator on. Adjust the contrast if necessary. "

Just need a small phillips head screwdriver and a CR1616 battery.

Do you know how to toggle between am/pm and military time? If you do, please email me at fischermh at netzero.com

You may need to replace the internal battery. It is found under the 4 AAA batteries and looks like a watch battery. This should solve your problem.

The battery is CTL 1616 and I had the same occurance when I opened up my model Casio model 3043. I needed to use the battery to test my model 2767 and find out if a new battery would bring it back to life (yes, it still lives). After replacing the battey back into my 3043, I jumped the (ac) to (-) and at first the watch would indicate all was well but then it would revert back to "open". I tried over and over to try and get the "open" display to clear but I was not successful. I then thought to go ahead and replace the back on the case to see if the three contact springs would change the display and sure enough, "open" no longer was in the display. The watch works perfectly as before. As for the 2767, as soon as I jumped the (ac) to (-) the "open" display went away. There is only one spring contact to the back case on the 2767 model. Unfortunately I do have an extra spring that fell out when I opened it up and I have no clue as to where it goes. I have not found anyone who can help me on the location for the shorter spring. Any advice would be most helpful.

Screen contrast problem. When the calculator lost power the contrast was reset to zero.
If new batteries, both AAA and Memory battery CR 1616, then press ON, then 2nd (yellow
Key), then UP arrow, More UP arrow if desired contrast is needed more. You should see the
display or screen effectively. It is not that it would not turn on, it was just that you couldn't
see the display, it was set too low for observation............................It was on just couldn't see it.......

I have the same problem with the calc not responding to removing one batt and reinstalling while holding clear, etc. My fix is to hook up wires to the battery leads and plug the wire into a 120 volt outlet. Watch it light up, but do NOT breath the smoke as it is extremely toxic. ;-) lkw