BLF Kronos X6 weird malfunction when bumped

Hello there, I’m new here!

I just got a BLF Kronos X6/X5 set and have a problem with it that I could not find mentioned on this forum yet - I hope I didn’t overlook something, if I did, I am sorry.

Basically, the light works great until it is subjected to a sharp “bump”. Most of the time, tapping it against your knee or some other bone is enough. When I do this (or even set it down on a hard surface with normal force), the tailcap light dims slightly. Switching the light on doesn’t work, the tailcap goes dead, and the light has to be reset by unscrewing the tailcap.

I also have a BLF A6 which had intermittent contact between tube and head, which I solved with a bit of wire, but the A6 never “crashed”.

Is this a known issue? Do I have to resolder the tailcap electronics? Is there any other hint I should follow? Or is this a case for returning it?

the time I encountered a problem like that was with my convoy s2/qlite driver—-I didn’t torch the pill and pre-solder it before grounding the driver—-I simply soldered a blob to ground it—-well one good drop on the floor and the solder cracked loose from the pill and I got all sorts of weird behavior…… at the time I actually thought the driver was going bad…. after discovering via blf members how to presolder the pill, problem solved… check all of the grounds for the driver and check the tail cap ring and clean your threads

Could be a loose switch retainer ring. Pressing the switch reestablishes contact temporarily.

Ugh those spammers…

Anyway, just FYI my X6 mysteriously stopped having this problem. Now it just works, even though I did nothing….

It’s losing contact intermittently. Could be springs that need to be a little longer, or a longer battery. Make sure the tail switch retainer ring is tight. Whatever it is, it’s a contact issue. No big deal. You’ll figure it out.

I just replaced the spring in my c8 and also added a copper pat on top of the spring which solved an inadvertent mode changing problem