There are two copies of each APU dissertation, and these are located in two places. The first place would be in the stacks (the books you can check out) of one of the three APU libraries, depending on the topic. This copy of the dissertation is available for check-out. The second place is in the Thesis Collection, which is currently located in Stamps Theological Library. While you won't be able to check out any of the Thesis Collection copies, it is a convenient way to see all APU dissertations in one place.
You can do the following catalog search to see all of the APU dissertations (click on image):
Just type in "Azusa Pacific University", change "All fields + text" to "School name/code," and hit "Search."