simple Kudos thread!
I had to hold down the S2 (USER/BOOT) button near the microSD card, while applying power to the board (by plugging in USB cable) in order to boot this firmware and extract the eMMC image. Pressing RESET while holding the S2 button did not work. After several seconds, I released the S2 button and then the LEDs started blinking. It seems the boot sequence doesn't proceed while S2 is being held down.
Edit: A further test shows that holding the S2 button for too long (15+ seconds) causes the board to turn off.