I have issues turning on my TI-Nspire using TI-84 Plus SE keypad

The standalone version of the OS for the TI84Plus/TI84Plus SE are not for TI-Nspire with TI84 keyboard. The 94 Plus part of the TI-Nspire is updated when you update the OS of the TI-Nspire. The version numbers are different.
To update you TI84 portion of the TI-Nspire, update the OS for the TI-Nspire. Thy are now at Version 3.2.3.1233

The standalone version of the OS for the TI84Plus/TI84Plus SE are not for TI-Nspire with TI84 keyboard. The 94 Plus part of the TI-Nspire is updated when you update the OS of the TI-Nspire. The version numbers are different.
To update you TI84 portion of the TI-Nspire, update the OS for the TI-Nspire. Thy are now at Version 3.2.3.1233

It seems to me that you get the loading bar when you switch keypads. I just switched keypads, and when I reinserted the TI84 Plus keypad back again I found my last TI84 Plus screen contents still displayed.
As to the RAM cleared message, it probably is related to the batteries being depleted.
To verify battery charge level, you may use TI connect.

Yes, you can change the faceplate of the TI 84PLUS Silver Edition only, not the TI 84 Plus. Face plates are available for purchase at the TI online store.When you go the online store, select the country, then the calculator model. You will find them under accessories for the TI 84 Plus SE.

Hi,

Welcome to Fixya. To be able to fix the issue please click on the link below. It provides the steps on how to clear the error message.

TI-84 Plus Silver Edition 2.43 RAM cleared Fix

If you hve questions please let me know. Thanks for using Fixya.

And why, pray tell, would you do such a thing? You will ruin your Ti84 Plus Silver Edition and will not have a working TI89. Besides, TI connect will refuse to transfer it.
If you like the capabilities of the TI89 Titanium, buy a cheap or used one on e-bay or amazon.com and spare your TI84PLus SE.

Remove the TI84 Keyboard, insert the TI-Nspire keyboard and try to reset the calculator with a starightened paper clip.Calculator has a reset button on the back.

You cannot do it with this calculator. It does not have a Computer Algebra System (CAS). Try a TI89 Titanium, a TI 92PLUS, a TI 200PLT or a TI-Nspire CAS.
However, they may exist other programs on education.ti.com or ticalc.org. Search these sites and you may be lucky.

Yes we changed out the batteries on now the TI-84 will not turn on HELP

Yes, the Ti nspire not only functions as a ti83 but, also operate w/ nice advance math software that any teacher would envey. It comes with the ti83 keypad plus software and great instructions to help the instructor at all levels of math learning. I don't know any better and it is a beautiful plan that ti has set up.