MAMP : Mysql won't turn on

twob.net has a pretty good fix for it. Go Into terminal and type in

killall -9 mysqld 

Check it - http://twob.net/journal/fix-for-mamp-mysql/. Worked for me

What I have found is that at times more than one occurrence of mysql is running. What I do when MySQL will not start is I first quit MAMP, then I go into the Applications/utlities and open the Activity Monitor. From there I search for "my" which should bring up any mysql's that may be running. I then either quit or force quit mysql. At that point I'm able to open MAMP with a working MySQL server.

Hope that helps.

With a new/clean install of MAMP 4.1.1, I had the same problem.

When running: /Applications/MAMP/bin/startMysql.sh

MySql reported:

mysqld_safe error: log-error set to '/Applications/MAMP/logs/mysql_error_log.err', however file don't exists. Create writable for user 'mysql'..

So, I ran touch /Applications/MAMP/logs/mysql_error_log.err and tried again with startMysql.sh. It worked (but it wasn't quite "by itself")!