Henk_Lu
Flashlight Enthusiast
I heard back from Walter via email. He said leaving the battery in with the knob screwed down (for dim) could result in the spring or whatever could compress. He recommends unscrewing the knob and let it sit for 24 hours to decompress.
Mine has been lying unscrewed for 48 hours now. I checked the system with my finger, it should work normally now.
If I had known how the system worked before, I would never have let it for months with the know turned in. Compressed springs always ge tired and this one needs to push the piston completely back for maximum output. In fact, it is like the opposite of a piston drive, where the springs needs to retain the piston back to not make a contact. What's more, this is not simply on/off, this controls brightness from min to max. I also understand now why the brightness goes back a bit, once you leave the know, it's thread play. Same thing for pushing the knob to make the light temprary dimmer.