I have also been through this problem,
First i tried setting my password of root to blank using command :
SET PASSWORD FOR root@localhost=PASSWORD('');
But don't be happy , PHPMYADMIN uses 127.0.0.1 not localhost , i know you would say both are same but that is not the case , use the command mentioned underneath and you are done.
SET PASSWORD FOR [email protected]=PASSWORD('');
Just replace localhost with 127.0.0.1 and you are done .