For Test, I´ve created another BD on same server, and it starts OK!
On my udump directory, i´ve found this message: "ksedmp: internal or fatal error
ORA-00600: codigo de erro interno, argumentos: [711], [1], [1015398872], [U¤ÿ€” ], [], [], [], []
Current SQL statement for this session:
/* OracleOEM */ ALTER DATABASE OPEN "
and nothing else!

Please, help, I´m loosing a lot of hair trying to fix it. !!