XE503C12 (Samsung Chromebook 2) not booting

[dumbnerd08]

Hello.

I have followed the instructions to flash Arch Linux ARM on my Micro SD and have inserted it into the Chromebook's Micro SD slot. I have made sure to enable USB booting as per the installation instructions. When I get to the screen that says "OS VERIFICATION IS OFF" and I press Control+U, the screen goes blank, the device makes a tone, and the screen returns to saying "OS VERIFICATION IS OFF."

What am I doing wrong? What do I need to do to make it work? I bought the device specifically to run Linux so I'm quite sad that this doesn't work.

Thank you.