Electrical – Why won’t the bulbs light up brightly in the European chandelier

You shouldn't have any issue. Alot of ballasts are rated 120v/240v. A regular wall outlet is usually 15a 120v. Which you should be fine. Is this a t8 t5 or t12 fluorescent light fixture. I mean it is possible that you have a bad ballast that is only providing the proper power to the socket for only the bulb that lit. Try taking the bulb that is lit out of that side and switch it to the side that isn't lit. That should give you a rough idea that something is wrong. Check the connections at the socket of the side that isn't lit make sure the wires are actually in the socket. But again test the other side with the good bulb. sounds like a bad ballast in my opinion. But again no...plugging it in shouldn't have hurt anything. Getting power that way isn't really any different than hard wiring it.

This question is old, but it just hit 1000 views so I thought I'd post the answer.

The 12V PSUs were all at end of life, and were failing. It may have been that the 3.5W bulbs were too low power to work, but either way I ended up replacing the lot with new sockets and LEDs. If I recall these are not stepped down 12V but run off 240V so don't need transformers. I could be wrong about that, it's over a year since all this happened