My Rephone Create Kit arrived today, and I assembled it as per the instructions.
“Hold the power button for 2sec…”
1… 2…
…3… 
There is a slowly blinking green light, and if I attach it to a computer, sometimes I can see it as a USB storage device, with several .txt files (including settings.txt).
However, there is no output on the speaker or screen.
What have I done wrong?
My Samsung Micro-USB cable (the one shipped with the Galaxy S6) seems to get abnormally warm when connected to my RePhone, if that helps.
EDIT: also, when I hold the power button, the LED goes green-purple-slow flashing green.
I’m an idiot. 
Turns out my LCD cable wasn’t quite seated. I took it apart, reseated the cable, and it works now!
I changed the cable and now everything works fine.
Scusi, allow me to explain myself clearly: when I connected the audio module, the screen went dark. Turns out the cable was somehow shorting it. I swapped the cable and ever since both the screen and the audio module work fine.