DownSights writes “As always, as per the zombies’ “tradition,” turning on power is the first step in any zombies map. Similarly, you need to first turn on Firebase Z’s power to access most of the map locations.
If you’re new to Firebase Z, then this guide is exactly what you need. This article walks you through the process of turning on the power to Firebase Z and building the Pack-A-Punch machine. These are the fundamentals of any map in zombies’ mode.”
Source: N4G PC Firebase Z – How To Turn On Power & Build Pack-A-Punch Machine