Bricked phone after downgrade and unrecognized to pc

Bricked phone after downgrade and unrecognized to pc

Hi guys,ive bricked a year ago an n73.Ive try to downgrade to another language software and.the flash was failed.now the phone boot up be a little time screen white then logo appears and than phone shut down.If i press constantly the button the logo appears but if i release its shut down again.I've send it to a service but it say he can't do anything.What can i do?Its a good phone i don't wanna garbage him.How can i make it back alives