I have an 8330 with Verizon wireless as my service provider. My device was working fine, suddenly the keyboard stopped working. The device turns on, calls come in, IM comes in, and the roller ball works. None of the keys work. I cannot answer calls, cannot open any applications, cannot even turn the device off. The cursor moves around but that is about it. It's as if my key board has been locked or the keyboard just stopped working.
try pulling the battery out for 30 seconds and putting back in and lettinng it reboot. A battery pull is usually the first thing to try. If that does not work someone else more knowlegeable than I will probably have an answer for you.
Yes if you have a warranty on it I suggest you take it in also. There is no need in you worrying with something that maybe cannot be fixed anyway. Good luck...
As suggested in this thread, as well as the exact same one you posted in the 83XX forum, take it back to the store for warranty exchange if the phone is still covered.