Some lights suddenly stopped working

Question

I come home to my wife and kids telling me that suddenly, basement, living room, and hallway ceiling lights stopped working. I try flicking switches on and off and nothing. Here is some information:

1. All 3 lights are flush LED mounted lights. One of them is a hue light.
2. I have gone to the basement to the electrical panel and have switched every single switch there on and off (including master switch). The reason why I did this is because I do not know which switch is responsible for lights in living room, hallway and basement. The three lights are still not working after this.
3. The light switch responsible for hallway is functional because it has three switches. One for light in garage, one for light in hallway near stairs (which is the one not working) and one for light in hallway on second floor near the stairs. Or maybe this info is not relevant, but I felt like I should include that just in case.
4. My kids and wife tell me that the light suddenly just went out, while they were busy taking something out to backyard.

I have very little electrical knowledge beyond building basic stamp robots, and very little money to spend on multiple electricians. Best I can afford is one competent electrician, but if possible I would like to avoid such costs since most electricians I called in my area charge 300$ starting until they figure problem out. Can someone tell me if I can somehow troubleshoot the problem please?

UPDATE:

I tried following things:

1. Reset every single GFC outlet I could find and that didn't yield anything.
2. Remove all ceiling light fixtures and check for burn stains or loose connections. Nothing was burned and all was screwed on well.
3. Change one of light switches into a plug and then plug that into a working outlet. Once I did that I found out that all lights started working.
4. Use that pencil thing (or whatever it is called) to check if wires had electricity. The wire coming out of the electrical panel did have power, but going to the lights didn't.

From this I have deduced that the wires coming out of the electrical panel and going to the lights was the problem, thanks to advice from Harper.

Since I suck and do not know what to do I ended up just running a new wire from the first light to the electrical panel, installing a new breaker and connecting the wire to it. After that everything worked perfectly!

Thanks guys!!! Saved me a lot of money!

Answer 1

Well, most likely it is a loose wire. Circuits are allowed to be wired in a "tree" topology (each box gets power from only 1 place, but feeds any number of downline places; cables never loop).

However, usually circuits are done in strings, typically with branches for either the switch or the lamp.

A failure like this is usually a bad connection, either at the last "good" point in the string, or the first "bad" point in the string. The trick is knowing how the strings are laid out, since you don't have X-ray vision.

All work should be done with the main circuit breaker off, because houses are full of surprises like stolen neutrals (a circuit 1 load returns power on circuit 2's neutral).

This isn't me "dumbing it down for you", only fools disconnect wires with the power on. Professionals will have the power on for testing, but will rewire cold because it's faster and less dangerous.

Unfortunately most modern construction is made using "back stab" connections, where a wire is jabbed into the back of a switch. It's impossible to inspect those. Conventional advice is to twist the wires out of the backstabs (they can't be used twice) and shape a J-hook into the wire and put it on a side screw (lots of videos on doing that properly).

A neutral wire might also have developed a bad connection. That can happen in "wire nuts" - those are easier to inspect, just hold the nut and firmly tug 1 wire at a time. If it comes apart, it's no good! Needless to say, you'll want the power off when you do that.

Answer 2

Harper gave the right answer, but before you start randomly opening outlets, you may be able to find the culprit without opening any outlet boxes.

Put a helper in the vicinity of the non-working lights and tell them that if the lights come on, they must immediately call out to you loud and clear. Then you go around the house and methodically bang hard on the wall very close to each outlet and switch that has even a remote chance of feeding the dead lighting circuit. Bang with the fleshy part of your fist so you don't hurt yourself.

Sometimes, the loose wire nut or backstab will re-connect from the vibration from your banging. This could cause a momentary flash or the lights might stay on. In either case, if banging near a particular outlet or switch gets results, that's where the bad connection is, and you should then follow Harper's instructions.