Procedure to drop and recreate the dbconsole

Drop the repository manually using following procedure.
Connect to the database and execute following sql.

a. drop user sysman cascade;
b. drop role MGMT_USER;
c. drop user MGMT_VIEW cascade;
d. drop public synonym MGMT_TARGET_BLACKOUTS;
e. drop public synonym SETEMVIEWUSERCONTEXT;

Remove HOSTNAME_SID directory from $ORACLE_HOME from both the nodes using.

$rm -rf $ORACLE_HOME/<HOSTNAME_SID>
$rm -rf $ORACLE_HOME/oc4j/j2ee/OC4J_DBConsole_<hostname>_<sid>
You would replace the values in the <> with the correct values.

Connect to server and set the environment for the database ORACLE_HOME
and ORACLE_SID

$ORACLE_HOME/bin/emca -config dbcontrol db -repos create