So the knobs work, but the keyboard doesn't? Does it generate sound if controlled by external MIDI? Ensure all the MIDI settings are set to receive/send data correctly via the Ctrl menus.
Is Local (Keyboard) control turned Off in the Ctrl settings? This would disengage the keyboard.
If the unit generates sound from external MIDI but the keyboard still doesn't work you could open the TI up and double check that the ribbon cable is properly seated and connected to the keyboard. If the TI is like my Indigo, you don't have to disassemble the whole unit, you can gain easy access to the keyboard itself just by unscrewing just two specific parallel lines of screws under the base, and the keyboard slips out and will show the ribbon cable/connector.
http://infekted.org/virus/showthread.php?t=31443
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PS > And another thing! Will the Ti|3 have user customisable/importable wavetables?

A ribbon-controller or XY-Pad might be nice, too, please! Thanks!