Double check the config.php file you edited for syntax errors. It’s possible that your host has PHP error reporting turned off, so when a parse error occurs only a blank page is displayed.
Is it an apache server? Is it running current versions of MySQL and PHP? Does your host support mod rewrite? Do you have the correct location to your database? Sometimes the default value for this is incorrect.
When you uploaded (i am assuming ftp) to your host where you in ascii mode?
Next What are the permissions of the files on the host? Most GUI ftp clients will show this, I prefer Filezilla. All .php files need to be Owner RW, Group and other R
Also I am assuming this webhosts makes error logs accessible
what does it say in there?