The camera doesn't turn on

Hi!

My Canon sx730 camera was working very good until a few days ago when I took some pictures under the rain. Now, when I try to turn it on, in the display appears the icon "BUSY" and nothing happens. Then if I press the shot button it start working as nothing would happen. But in facts after a few pictures the battery drops and I must charge it again.

Maybe someone can give me some hints?

Many thanks in advance,

Carla.