Ti-84 plus i tried turning on the calculator but it wouldnt. then i tried replacing the batteries and it still wont turn on. then i tried the contrast and it still didnt work. then i tried resetting the calculator but still nothing. any suggestions?

If the TI-84 SE does not function even though you are sure that the
batteries are fresh, you can try manually resetting it by following steps:
1. Remove all of the AAA batteries from the graphing handheld.
2. Press and hold the ON key for ten seconds.
3. Replace the batteries.
4. Turn on the unit.
When you reset your graphing handheld, the contrast sometimes
changes. If the screen is faded or blank, adjust the contrast by
pressing 2nd and releasing up-arrow or down-arrow keys.

It could be that the main batteries are drained and are no longer able to supply power to the calculator. Replace the AA batteries with a fresh set. After replacing the batteries the display may become too dark or too dim. To set the correct contrast
Press [2nd] key and release it.
Press and maintain pressure on UpArrow to increase contrast (darken screen), OR on DownArrow to decrease it (lighten screen). If you overshoot your intented contrast you can revert the processs.

Remove all four AAA batteries. Press and hold down the ON key for at least ten seconds. Replace the batteries. Turn the calculator on.

Hello,
Here it is from the horse's mouth (TI Knowledge base)

For the TI-83 Plus Family, TI-84 Plus Family:


Caution: The resets described in these troubleshooting steps will cause a loss of applications, programs and data. If at all possible please create a backup using TI Connect™ first.

1. Try a new set of AAA batteries.
2. Adjustthe 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 [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.
4. 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". Follow the instructions for the TI83-family or Ti84 Plus family to reinstall the calculator operating system (see below.)
5. 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.

Reinstalling the OS fot the TI84Plus

How do I correct the Error Waiting...Please Install Calculator SoftwareNow message on my TI-83 Plus family or TI-84 Plus family calculator?

If an operating system (OS) update fails or is interrupted, the calculator will be in an inoperable state with the message Waiting...Please install calculator software now.The most common cause of a transfer being interrupted is updating the operating system on a calculator with low batteries. Users will need touse the TI Connectivity cable and the TI Connect to send the operating system to the calculator. Make sure to have the latest version of TI Connect installed on the computer.
In order to install the software please follow these steps:
1. Connect the TI Connectivity cable between the computer and the calculator.
2. Click on Start >> Programs >> TI Tools >> TI Connect >> TI OSDownloader
3. Follow the on-screen directions to reinstall the calculator's OS.
If the message "Error! Press any key to turn unit off. Then turn unit back on." appears on the graphing calculator, quickly, remove one battery from the calculator and reinstall it while the transfer is taking place.

Hope it helps.

From TI FAQs:

What troubleshooting can I try if the TI graphing calculator will not turn on?

For the TI-83 Plus Family, TI-84 Plus Family:
Caution: The resets described in these troubleshooting steps will cause a loss of applications, programs and data. If at all possible please create a backup using TI Connect™ first.

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 [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.
4. 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". Follow the instructions for the TI-83 family or TI-84 Plus family to reinstall the calculator operating system.
5. 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.

This is from TI FAQS:

Solution 11900: Troubleshooting a TI Graphing Calculator That Will Not Turn On.

For the TI-83 Plus Family, TI-84 Plus Family:
Caution: The resets described in these troubleshooting steps will cause a loss of applications, programs and data. If at all possible please create a backup using TI Connect™ first.

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 [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.
4. 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". Follow the instructions for the TI-83 family or TI-84 Plus family to reinstall the calculator operating system.
5. 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.

Could be that your calculator needs to be reset. Take out the internal battery that is located in a tiny door with a screw right above the 4 AAA batteries. Leave this out for about 8 hours and put it back in. Put in the AAA batteries and the calculator will be reset and may work.

try adjusting the contrast up using 2nd + up
just keep pressing it and it should turn back

This is kinda a weird situation. Because it's usually the other way around. Your ram will clear if your calculator is frozen. So take out all 5 batteries from the back. Even the back up battery. Then reset it again. 2nd then + then 7 then 1 Then 2. Good luck.

Did you try to adjust the screen contrast?