How to determine where the zero burned out in the apartment?

Good afternoon Dear forum users! Enlighten please inexperienced. I live in a panel 5-storey building, built in 1978. A few days ago, sockets stopped working on one side of the apartment! There were no shorts, pops, sparking. Having read the different sites, I came to the conclusion that the zero burned out, because both wires (phase + zero) in the sockets show a voltage of 12V. Now the question is: How to understand in which section the gap occurred? Sockets checked everything, the wires are intact! Can I disconnect all outlets from each other and leave power only on that outlet that is powered directly from the shield in the entrance and to determine if there is current in this area ?! And then alternately connect other outlets to the circuit to determine in which area the malfunction is ?! Or am I misunderstanding?
I apologize for the confused text, I just never had anything to do with an electrician!