CDbConnection failed to open the DB connection: SQLSTATE[08001]: [Microsoft][SQL Server Native Client 11.0]Named Pipes Provider: Could not open a connection to SQL Server [53].
CDbConnection failed to open the DB connection: SQLSTATE[08001]: [Microsoft][SQL Server Native Client 11.0]TCP Provider: Se produjo un error durante el intento de conexión ya que la parte conectada no respondió adecuadamente tras un periodo de tiempo, o bien se produjo un error en la conexión establecida ya que el host conectado no ha podido responder.
It looks like your recent attempt used the TCP Provider instead of the Named Pipe provider. Perhaps it’s a SQL Server instance using some other port? Why not try the plain PHP code in the post I linked to. I think this is not a Yii problem (not doing programming nowadays).