You just realized that the 'display' may be damaged, or the potentiometer is defective, or the power supply is not connected...or who knows, you still haven't connected whatever you wanted to the correct pin. Seriously speaking, haven't you got an implicit message from mine that answers can be as vague as the posed questions? In general, people attach pictures, sketches, circuit description, or anything else.
In other words we have no idea what you have.
How can we give an answer when you supply no information, other than a power supply you have doesn't work?
My vehicle doesn't work when I try to start it.
What's wrong with it?