To find access cards and weapons, you'll need to be dedicated to fully exploring Citadel Station from the System Shock remake. However, that doesn't apply to those looking for the Interface Demodulator on mission level one.
Master Jettison: Fix Power Relay (Guide) | System Shock Remake (2023)
The Interface Demodulator is one of the many story items in System Shock remake, and it gets its own waypoint marker. However, if you are not playing on Mission level one, then the Interface Demodulator will be hidden from you, just like everything else in this game. So, if you want to fix Subsystem Relay 428, then this is where you can find the Interface Demodulator System in System Shock remake.
The Interface Demodulator is a key story item in the System Shock remake. You'll need it to repair Relay 428. Head to the third level of Citadel Station—Maintenance. You can only reach this sector from the south side of the Research Labs, as each deck is separated by elevators with a limited number of floors you can visit.
The entrance to Maintenance drops you off on the south side of the deck. You'll want to head north, towards the second elevator on this level. The third and final elevator is more central and will likely be the last one you encounter on your first visit to Maintenance. Enter the room directly next to the north elevator and climb the ladder in this small room.
