USB Connection & Safe Power-Down for Racks

Connect the rack USB uplink to the control PC before inserting all devices — verify hub detection first.

Use powered industrial hubs only; unpowered consumer hubs cause voltage drop and random ADB disconnects.

Keep data cables under 1.5m where possible; longer runs need USB 3.0 active extensions.

Safe shutdown: stop active QA jobs → disconnect apps gracefully → power off rack PSU switch → remove devices if servicing slots.

Never hot-swap motherboard nodes while the power bus is live unless your lab policy explicitly allows it.

Document which hub port maps to which slot ID — included in PhoneFarm ICU packing list.