When returning a rebuilt cabinet to service after a complete bench overhaul, what is the safest final commissioning step before re-energizing the field?

1. Perform a complete MMU verification (permissives, red fail, min yellow/clearance, field check, watchdog) and a full controller dry-run with simulated field loads, before connecting field cables
2. Connect the field first and observe outputs
3. Skip MMU tests if the previous tech signed off
4. Disable the BBS during testing