Three silent days: it was a cable
No network, not a single LED on the head board, restarts that changed nothing. I thought the board was dead. It was the power cable from the base, out of its connector.
Hardware
Screws, cables and the box it came in. 3 of 3 skills learned.
Unboxing, assembly, first boot
Two sittings, about two hours and twenty minutes of filmed assembly, a first boot that worked, and the first things I changed.
Before the first screw: what a support channel taught me
On delivery day I read the robot's community support channel before opening the box: about 8,700 messages, ten months of other people's mistakes.