Troubleshoot TCP/IP access to MDT database

Using SCCM with MDT 2010.1. Have created the database. The client does not use named pipes so I am trying to use TCP/IP authentication but not working

So I have got the client to create me a SQL login which they've done with DBW rights to the MDT database

I've also create a share MDT2010 and shared out as MDT2010$

Have added DBID and DBPwd entries into customsettings.ini to authenticate but to no avail

How can I troubleshoot why SCCM cannot connect to the MDT database?

Thanks

Ian Burnell, London (UK)