Is there a way to run the Apple Hardware Test without an optical drive? I have a MacBook Pro 13", Mid-2009 and it came with Mac OS X 10.6 Snow Leopard. As I understand it, that means I would have to use the DVDs provided by Apple
to boot into Apple Hardware Test. The problem is I don't have my optical drive anymore since I swapped it out for an extra HDD. How can I run the Apple Hardware Test?
This answer Diagnosis or Hardware Test on a mid 2009 Macbook Pro with MacOS 10.9.2 discusses a GitHub page https://github.com/upekkha/AppleHardwareTest which has assembled various versions of the AppleHardwareTest which you can download and install in a specific place on your harddisk. This allows you to run the test without a working CRROM.

It worked for me on a Mid 2009 Macpook Pro.