Shutter seize up on dmc fz300.

Shutter seize up on dmc fz300.

My Panasonic Lumix dmc fz300 has a shutter that is seized up viewfinder and pull out screen are black even with the lens cap off. All the menus work and display on screen even playing back images from memory card. Have tried recharging battery fully and putting new memory card in has no effect. Is it fixable is there something I can do?