I have a Raspberry Pi 3 Model b+ from Element14 ordered through Amazon, I'm trying to set up RetroPie on it and have followed every step, up until the first time you boot the Pi, and mine just won't start up. I get the power light, but no activity on the display, and no other lights blink or light up on the board. I'm running with a Sony 32GB micro SD, and a NorthPada AC Adapter with a power switch, output is 5V-3A. Any thoughts?