As soon as I read the thread title I suspected that unit got wet - most electronics do not like water and key-response is almost a sure sign things got wet.
A suggestion from Blackberry forums is to place the unit in a closed contained of dry white rice and leave it for a few hours/days. It absorbs the moisture. Another is to go to a hardware store and buy dessicants (sp?) and seal the unit with them. Slow heat, very slow heat - top of tv, computer. More hair dryer time - but low heat.
Good luck (the Blackberry has water damage stickers so Rim can tell if exposed to moisture - maybe Amazon does not go that far and would replace the unit)