load database blank screen

You probably don't have the PHP mysql extension installed.

No that's not it.  phpinfo() show mysql and I wrote a little PDO script to read from a table.

This may still be correct. the mysql extension has been deprecated and you should not use it. Try mysqli (stands for mysqli improved) instead. I can't seem to locate any documentation links that describe what all the valid options are. The CI 3 docs look fairly helpful.

EDIT: just to be clear, the old mysql extension may not exist in your new PHP version. You would still see some MySQL configuration information in phpinfo, but that would be referring to mysqli ("MySQL Improved") or perhaps PDO or something.