Backing up a MacBook Pro without a screen? I have a MacBook Pro (Retina, 2013→2014) with a mini PCIe SSD (512GB, Solid State Drive).

There is a problem with my current operating system causing the video output to be corrupt. Native screen is blank. HDMI output is a bunch of crazy, snowy, flickering lines and such.

Although I'm fairly confident the rest of the system is working underneath the façade (or lack thereof). Apparently, it's not a GPU / hardware problem as I first thought (According to the in-store Apple tech "genius" guy; I was reluctant at first to agree, but now convinced).

I tried reinstalling the OS via safe mode recovery methods. No dice, but an externally (network) booted version of OS X ran perfectly. So I'm going to start again with a clean slate; a fresh factory-style install of the OS.

The problem is: I want to backup my personal data; obviously this has do be done first. Of course this is difficult without being able to see what I'm doing. And safe mode doesn't appear to have access to any personal data.

• Is there an adapter that I can use to connect this storage device (mPCIe) to my other laptop (USB)?

• Failing that, if there is another way;  any other methods or suggestions are also welcome.

Thanks.
If you have another Mac and a Thunderbolt cable, you can use Target Disk Mode. When starting up the problematic Mac press and hold T. Then connect the cable to the other Mac. It should mount and you can pull the files off like any other disk, provided its not encrypted.

Since you also mentioned you using NetBoot, consider booting into that image and copy the files as needed.