Lighting – Help on identifying light socket? (Japanese apartment)

I once performed a direct study on this subject. I built an apparatus to power-cycle a T12 fluorescent lamp every 60 seconds and an identical lamp every 12 hours. I used both recording watt-meters and standard household electric meters to measure the power consumed.

I expected that the power consumption of the filaments during preheat would be different from the power consumption of the ionized arc. Probably more, but possibly less. I was surprised to find that even after 96 hours I detected no measurable difference.

I could only guess that the ballast limited the filament current just as it limited the ion arc current.

This was so long ago that there was only one kind of ballast available, what we now call a dumb ballast. I don't know what the result would be with a modern fixture.

I also applied an oscilloscope to the line side of the ballast and I could see a power spike that lasted less than 1/120 second. I couldn't get a good idea of its magnitude. I theorized that the meters used moving parts and could not practically respond to an event of such short duration.

My conclusion was: Yes, a fluorescent lamp does consume a power surge on startup -- but you don't pay for it!

You probably have 4 rails there, just two happen to be in-line, on either side of the power input (gray block in center.)

Your problem is likely at the right side (in the picture) corner connector. Given that the power supply appears to be shared, the power supply would seem to be fine given the working lights - but the conductors are not conducting around the corner. Exactly why is hard to determine remotely, but that's where to look.