In your first code snippet, you are still using the uppercase SID. Try it lowercased!.
tnsping works with the identifier, which most often is not the same as the SID.
$ head -4 $ORACLE_HOME/network/admin/tnsnames.ora
oradb_btest = ( DESCRIPTION = ( ADDRESS_LIST =
( ADDRESS = ( HOST = oradb )( PORT = 1521 )( PROTOCOL = TCP )))
( CONNECT_DATA = ( SERVICE_NAME = basetest ))
$ tnsping oradb_btest
TNS Ping Utility for HPUX: Version 10.2.0.4.0 - Production on 13-MAY-2
Copyright (c) 1997, 2007, Oracle. All rights reserved.
Used parameter files:
Used TNSNAMES adapter to resolve the alias
Attempting to contact ( DESCRIPTION = ( ADDRESS_LIST = ( ADDRESS = ( P
+ROTOCOL = TCP)( PORT = 1521) ( HOST = oradb))) ( CONNECT_DATA = ( SER
+VICE_NAME = basetest)))
OK (90 msec)
Enjoy, Have FUN! H.Merijn