ora 28000 account is locked 

Using SQL*Plus to Unlock Accounts and Reset Passwords
1)Start SQL*Plus and log in as the SYS user, connecting as SYSDBA
$ $ORACLE_HOME/bin/sqlplus/nolog
CONNECT SYS as SYSDBA
Enter password: sys_password
2)Enter the command ALTER USER account IDENTIFIED BY password ACCOUNT UNLOCK; to unlock an account.