I have a desk lamp, which is already more than 20 years old and therefore has a very old, so-called conventional ballast. That's inegriert in connector and is characterized by high weight. Apparently there are lamps that do not work with these old ballasts. You only flicker briefly when you turn, and but do not light it. I had bought one of those. However, these Osram Dulux S 11W / 840 G23 worked right away and offers nice bright white light at my workplace.
