To get into Diode's workshop in STALKER 2 is part of the quest The Price Goes Up, and while it seems like you'll need a keycard at first, in fact no such device is necessary: there's another route in.
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What Does a Diode Actually Do?

A diode is a tiny component with a powerful job—controlling the direction of electrical current. This video explains how ...
The local tech has gone missing, and the only other solution is to walk back to Zalyssia. During a certain point in the story, Diode will go missing from his usual spot in the Slag Heap of the Garbage ...