All I did is change password for root
I'm not sure I can be of much help. If you changed the root password, then you have to change the info that is/was being used in config.inc.php for phpmyadmin.
You may also need to search these forums on phpmyadmin and root password. IIRC it was highly stressed not to change it via phpmyadmin. I think you will find instructions on how to reset the root password via SME so that other things won't break. It's been a while, but I think that is correct.
That is why I create another user that has the rights to mysql and use it.
Sorry, I can't help more.
JB