Halfway through my third winter my Lumotec IQ Fly Senso Plus (powered by a SON hub-generator) headlight has suddenly started fluctuating, after I returned from Christmas holidays. While riding in the dark (and darkness lasts 20/24 hours here this time of the year), my light semi-regularly switches from bright to faint and back to bright. The faint light looks like the standlight, so very much less than the bright light. I ride in the dark around 5 hours/week during around 5 months, so with around less than 500 hours of dark riding, the LEDs should still be fine — or do LEDs degrade much more quickly in the cold (<-20°C)? My own hypothesis would be as mentioned on this forum:
The flickering of the previous light could have been caused by adjusting the light when it has been firmly screwed down. This could cause the contact lip to turn in the housing and loose contact with the bulb. If this happens bend the lip forward again, and ease the mounting bolt a bit before readjusting
but I'm not sure if it applies to my model, I don't know what lip to bend forward and how. I've already firmly attached the plugs on the outside, but maybe something got loose on the inside. As I'm a bit afraid of starting to disassembling things I can't assemble again, I'd need some advice.
- What can I open, firmly attach, adjust, etc. in an attempt to tighten all connections that need to be tight, and how do I do this?
- What other problems may cause the observed behaviour, and how would I handle those?
(also posted at this Dutch forum)