My home electrical system is single phase, two wire (live + neutral; grounding is short-circuited to the neutral). I have no schematics as to how it is connected. However, there is a separate circuit breaker for the lamps.
Today the ceiling lamp in the living room stopped working. The lamped is controlled by a two-way switch.
After conducting a series of experiments, I concluded that the neutral connection is faulty. Namely, a light bulb lights up when connected to the output of COM2/live input of my ceiling lamp and a reliable neutral, but stays dark when connected to the same output of COM2 and the ceiling lamp's neutral.
As can be seen from the schematic above, there is no junction box in between the lamp and the central electrical box (or I can not find one). Somehow, somewhere, there are more lights, connected parallel to this one, for the next room. Some of them stopped working too.
What should be done in this scenario? I would like to avoid bringing down my whole ceiling - maybe at least to know where to cut.