I feel stupid asking the question: I've been looking for an answer for half an hour, but it seems that anybody else have figured it out.
I've got my first Raspberry Pi 3 model B. I followed the instructions to prepare the SD card, plugged the SD card into Raspberry Pi, connected an USB keyboard, a network cable and a PC HDMI monitor, and plugged the power, expecting something to happen.
But all that happened is that the power LED turned orange; it's not blinking, it just stays orange. Then nothing. The monitor remains off. The network indicators don't light up (neither on Raspberry Pi, nor on the switch). The keyboard numeric lock stays black as well.
I imagine there is something I should do to actually turn Raspberry Pi on. But what? I can see no buttons on the board.
What should I do now?