No power to the receptacles on a circuit, the breaker isn't tripped. there are no GFI's

No breakers are tripped and a circuit is dead.

There is a loose wire.

Let me explain how it works. Each 120V breaker has a black wire that leaves breaker box. The black wire is accompanied by a white neutral wire and a bare ground wire. These wires are sheathed in plastic, and altogether they make up a romex cable.

The cable leaves the circuit breaker box and travels to the first junction box. The junction box is a ceiling box that holds light or fan -or- a wall box containing switch or plug. As a general rule, the romex leaves the breaker box and travels all the way to a junction box located right in the area where lights and plugs are located. The romex does not stop at a junction boxes located in other room.

Inside the junction box, the romex splits and goes to the next junction box, and then to the next box, and the next.

So the plugs in one room are all connected together by a single romex cable that started back at the breaker box. And a single romex wire from the breaker box arrived at one of the junction boxes located in immediate vicinity of dead receptacle.

Here's what happened. A wire came loose somewhere between the breaker and the dead receptacles.

The loose wire is probably in a receptacle.

Here's what to do.
1) Breaker first: You can isolate the suspect breaker by identifying all other breakers. Then tighten screw on suspect breaker. Look for white wire and ground wire associated with the romex cable that connects to breaker >> tighten those screws on neutral busbar. Look for burning around suspect breaker. Is there a burning smell indicating breaker is bad?

2) Receptacles Next. Use ordinary tester. Test each receptacle. Receptacle has two rectangular prong holes and one round hole located below other two. The round hole is the ground. Breaker is turned on. Test each rectangular hole to ground. You have to test both prongs to ground.

The loose wire is right there in the vicinity of dead receptacles.

Test one receptacle and then move to next receptacle. At some point the tester will light up. Now click suspect circuit breaker to see if that receptacle is on breaker. Test receptacle with breaker off and breaker on. If that receptacle is on the suspect breaker, then a loose wire is inside that receptacle box >> or inside the next box. Many times, the wires are pushed into 'quick-connects' located on back of receptacle ... wires get loose ... you need a small screwdrive to release quick-connect, and then wrap wire around screw -or- replace receptacle

If none of receptacles show electricity, then loose wire is inside a switch box, or it is inside a ceiling box located in same general area. Check your switches first. Look for quick-connects, or signs of burning. Look for loose wire nut. Plug light into dead receptacle. Pull switch out with wires attaches. Power is on. Move switch around to see if dead receptacles shows electricity. Move to next switch. The loose wire is there somewhere.

Finally the ceiling box. Take down light and see if there is a loose wire inside. Look for signs of heat or burning.

All of the previous solutions to your problem are of very sound advice and should be used to troubleshoot your specific problem. I just wanted to add to the list of solutions given. I had a circuit in my home that when the breaker was off and voltage was tested at the switch, I still had a reading of .6 v , and with the breaker on, a reading of 40v. Non of the lights or plugs would operate on the circuit. I then traced the wire on that breaker from the problem lights and plugs, back to the breaker, finding a compromised splice in the wire. The splice was cleaned up and respliced, and low and behold, the problem was solved. Good luck to you....