Screen is "locked up"

I have the original battery, it still takes a charge and phone was working properly. dropped. no obvious external damage. pushing the round recessed button lower center, or the black on button adjacent to the sim card produces the same result. black screen appears for < than 1 second.

Screen has an image of the planet earth upon which is superimposed a boxed msg "waiting for activation". slide to unlock does not respond, and screen goes black. sim card swapped for a known working card, with no change in symptoms.

What do you think the issue is? What parts do I need?