This tutorial is to show how to fix the optical drive problem in your Mac Mini 2009.
The problem is that if the optical drive is dirty it keep ejecting the DVD movies or audio CDs without playing them. During the years the electronic devices accumulate a lot of dust and when the optical laser gets some of the dust the laser can't read accurate the DVD movies or Audio CDs for example.
I hope that this tutorial can help you to fix your 2009 MacMini.