I changed my root level password on phpMyAdmin. I was unsure where to enter the password itself, as it did not give me the option (login form). I wondered if it was the php.ini
I was being annoyed by the startup "access denied" error MAMP would show, even though I was able to access my site using phpMyAdmin or other SQL tools. I even found/updated the password in checkMysql.sh, repairMysql.sh, and upgradeMysql.sh. I did not notice the script called quickCheckMysqlUpgrade.sh and correcting the password in that fixed the startup error for me.