Ah, elevators. Perhaps the greatest symbol of humanity's conquest over gravity. Our heroes enter it, and with it, they can travel to any floor of the office building/dungeon/cave/whatever that they happen to find themselves in. But what's this? Oh no! Something's missing! Perhaps it's a button, perhaps a key, but without it, the elevator cannot function normally, giving our heroes only limited access to the office building/dungeon/cave/whatever until they can find the needed MacGuffin.
The trope's name is in reference to the theme song of the popular sitcom The Jeffersons.
The elevator for Joe's building is missing buttons (which Joe must recover to advance to each floor).
Tod and Billiam find an elevator missing a key. They take the stairs instead.
One of the buttons on an elevator is blank.
The hero tries to use the lift to avoid confrontations with a pair of thugs, but finds that he needs a keycard to use any of the buttons.
Pix needs to use the elevator to get past the first 2 floors in Chromatics Inc. but the elevators broken.