I have 4 recessed LED lights above my fireplace mantle that have been working intermittently (ie. they work for a few days, and then won't come on for months). This issue also affects the wall socket above the fireplace and an LED light in the pantry on an opposite interior wall. The recessed LEDs are on a dimmer switch which I typically keep turned on at night for low lighting for our dogs. I also keep it turned on when these lights/wall socket aren't working in hopes they'll eventually turn back on. Recently, after these lights/wall socket haven't worked for what seems like 6 months, they randomly came on, the wall socket worked, and the LED fixture in the pantry worked. Is there some kind of troubleshooting I can do to fix this? Replacing lights seems ineffective and this feels like a wiring issue or something.
The last time something like this happened to me -- a suddenly dead outlet -- I went to each outlet or wiring point on that circuit, which were all in the same room, and gave it a good sharp rap with the fleshy part of my fist. One of those raps restored the power to the dead outlet; the vibration re-connected a loose connection behind that outlet. I expected to find that a previous owner or his electrician had used the unreliable backstab connectors on the outlet, but it was merely a badly done wire nut that had come loose. I made a proper connection, pull-testing each wire on my new connection and re-tightening and pull-testing all wire nuts in the box. That fixed it.