My DVD drive wont open at times.

Hi,

The Xbox 360 uses a rubber belt that can either sometimes become loose/too stretched, becomes dirty with dust, it starts to slip, or it has come out of place etc, putting it back correctly, cleaning it with isopropyl alcohol or replacing the belt usually solves this issue.

There are plenty of guides on the internet about disassembling your Xbox to get to your drive and opening it.

I have posted a picture of the belt I am talking about, also make sure most of the drive is clean. :-)