After you have changed the DBA passwords, verify  that the data sources still work.
    
- Select .
- Select the System DSN tab.
- Double-click  default-cdb, then click Test Connection.   Look for a "Connection Successful" message.  
- Return to the System DSN tab.
- Double-click clusterdb_<cluster name>, then click Test Connection.  Look for a "Connection Successful" message.