Did you remember to alter the code in mainfile.php to reflect the path changes and database account?
Here's an example of what one of mine looks like using easyPHP.
Physical and Virtual Paths:
// XOOPS Physical Path
// Physical path to your main XOOPS directory WITHOUT trailing slash
define('XOOPS_ROOT_PATH', 'f:/web design/localhost/www/testing');
// XOOPS Virtual Path (URL)
// Virtual path to your main XOOPS directory WITHOUT trailing slash
define('XOOPS_URL', 'http://localhost/testing');
Database Account:
// Table Prefix
// This prefix will be added to all new tables created to avoid name conflict in the database. If you are unsure, just use the default 'xoops'.
define('XOOPS_DB_PREFIX', 'testing');
// Database Hostname
// Hostname of the database server. If you are unsure, 'localhost' works in most cases.
define('XOOPS_DB_HOST', 'localhost');
// Database Username
// Your database user account on the host
define('XOOPS_DB_USER', 'root');
// Database Password
// Password for your database user account
define('XOOPS_DB_PASS', '');
// Database Name
// The name of database on the host. The installer will attempt to create the database if not exist
define('XOOPS_DB_NAME', 'testing');
If the above is not configured correctly in mainfile.php, you'll get a blank screen.
The easiest thing I've found to do is to overwrite mainfile.php on the local server with a fresh copy.
Make sure you copy the install directory into your XOOPS root directory and change the permissoins on mainfile.php to rw-rw-rw.
Open your browser and piont to
http://localhost/xoops_root_directory/ and perform a new install using the database name, username, password, table prefix, and Admin account information that you used for your production site.
Then when you've finished the install on your local server, overwrite the database with the copy from your production site and change your permissions on mainfile.php to r-r-r.
If you exported the database with the 'Drop Table if Exists' lines in it, you wont need to dump the local database. It will be automatically overwritten. If you don't see the 'Drop Table if Exists' lines in your production site's sql file, just dump the local site's database before you import the production site's sql file.
Hope this helps.