PROD_BALANCE not working

Hi,

I have a problem with our rac server(2 nodes database).

All of my tns alias in tnsnames.ora are OK except for PROD_BALANCE which uses the load_balance and failover parameter.

[oracle@db01 ~]$ sqlplus apps@prod_balance

SQL*Plus: Release 10.2.0.4.0 - Production on Wed Apr 17 18:26:18 2013

Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.

Enter password:
ERROR:
ORA-12541: TNS:no listener

[oracle@db02 ~]$ sqlplus apps@prod_balance

SQL*Plus: Release 10.2.0.4.0 - Production on Wed Apr 17 18:26:53 2013

Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.

Enter password:
ERROR:
ORA-12541: TNS:no listener

=============
For TNSNAMES:
=============

[oracle@db01 ~]$ tnsping prod_balance

TNS Ping Utility for Linux: Version 10.2.0.4.0 - Production on 17-APR-2013 18:34:03