Blf A6 comes on and off based on threads

I have frequent problems with my A6 not coming on. If I unscrew the tail cap, it flickers on and off. I am sure this question has been answered, but my luck for finding this info isn’t doing so well.
Can someone point me to the cause/solution for this?

On a related note, I like the flashlight, but I don’t really love how it comes on in ultra low mode. If I have to get a new part to fix my my issue, maybe I can find one with a different sequence.
Thanks!
John

Cant you turn on memory mode to solve your issue with the light always turning on in low mode.

Check that the two retaining rings, one on the head and one on the tail cap, are tight.

You need to read about configuration modes.

After 15+ short taps, you go into so called configuration mode. After 15+ taps, light goes OFF momentarily and then there will be two sets of two blinks. The first set of two blinks toggles 7-/4-mode, and the second set of two blinks toggles memory mode on/off. You toggle a setting by turning off BETWEEN the two blinks.

To toggle mode memory, for example, after 15+ taps, light goes OFF, blink, blink, and then blink. You now turn off — before the second blink. You now set mode memory. Turn off the light. Turn on the light and go to Turbo. Turn off light and then turn on. You should now get Turbo.

It could also be your battery is to long for the tube? Are they still having this issue?

As mentioned by BLightSam — take tweezers or needle nose pliers and tighten the two retaining rings if they’re loose at all.

Wipe the threads with a clean cloth and maybe a dab of conductive grease (“bulb grease” or “nyogel” or the like)

Look at the springs — do they touch the battery with a sharp point, like cut off with wire cutters and left poking out? That can gouge and also bounce.
(look for scrape marks on the metal of the battery)

You can gently bend the very tip of a spring slightly in toward its attachment end to make the contact be a smooth and longer area of the wire instead, and a dab of grease on the end won’t hurt.

Thanks for all the responses! The led side ring was loose. That didn’t fix things though. I wiped the threads off on the other end, that seems to have fixed it. I have some waterproof grease at home. I’ll have to read the tube to see if that will work. An AT&T guy gave it to me.

Glad you got it running. The threads on the battery tube are anodized on both ends… If you still have trouble, try removing retainer ring on switch end and cleaning the threads under there where it seats in.

Is the battery protected? If so, try unprotected.

I’m using a Panasonic 3400 protected. Same cell I have always used in this light. At this point, the threads seem to have been the issue.

Some of the first batch had a little short tube/body and as a consequence contact was only made intermittently even with ‘regular’ length 18650. Your Panasonic is one of the longest one and thus may cause the contact problem. (Later batches fixed the problem with longer tubes.)

I bought mine in June of this year. I think it has the longer tube.