Hi,
many thanks for your hints!
Well, if I remove the bulb and heat it with the hot air gun - how hot should it become, is there a minimum/maximum? is it maybe worth cleaning the lamp with isopropanol?
(Actually, how does that lamp work? I read somewhere it is a gas discharge lamp, but with 6 Volts? seems a bit low, isn't it?).
At this moment I cannot yet measure the lamp housing temperature. But I ordered some thermocouple sensors for my multi meter.
Which one is the servo test pin? that one with the fancy waveform which then drives the SRD?
the visual impression of the light: it is not so bright, and I think it is more like purple-blue (it should be red-ish, right?).