BLF A6 FET+7135 Light Troubleshooting and Mod thread

Debugging is a process. The first thing to try varies with the problem. On a light that doesn’t come on the first thing I sound do is remove the tail cap and put a paper clip from the bare metal of the tube to B-. If you get light then the problem is in the tail cap. Loose retainer, bad switch, rubber button pressing on the switch and opening the contact(remember, a reverse clicky turns off with a half press which is just what happens when there’s no play under the button). A light that comes on when the switch retainer is tightened is could have a short somewhere on the switch pcb. Pics would help.

Thanks - yep having done that entire process on the previous light was going to go through it again.

However happy news - it just seems like it in turbo mode it cuts out on one protected battery but not the other. One can go to 7 and hold it, one goes to 7 but cuts out after half a second - I assume it’s tripping something. I can step back to 6 and it’s fine.

Probably the protection circuit of the cell.

+1

You want unprotected high drain to run turbo.

Or batteries with a known quality Seiko Protection IC.

Best Regards,

George

If it’s the protection circuit then it has to be reset correct?

On mine it does turbo for a moment then cuts out - but I can instantly switch back to level 6 and it works so not sure if that resolves whether it’s the protection circuit or not.

My understanding is that when protection kicks in then the battery is dead until the circuit is reset. So it doesn’t sound like your issue is due to the battery’s protection circuit tripping.

It probably depends on the protection circuit… For what i’ve experienced with a few lights and batteries, when the protection kicks in, it does reset by itself as soon as the light is turned off.

This happens to me with the TrustFire mini 01 and 02 for instance, using fully charged TrustFire protected 16340. On high the light blinks at full once quickly and then shuts off. Turning the light off and on again,the light comes on in mid mode. Once i’ve cycled back to high it blinks and turns off again. Once i’ve managed to drain a bit the battery on mid for a few minutes, then it can hold on on high. FWIW.

Thanks for the info. I don’t use protected cells but at least I know now that they work in different ways.

I read through all BLF A6 threads, but did not find anyone with the “problem” I have. Banggood made it right, just want to share, maybe someone else will get lights like mine.

The tail cap of my A6 does not screw in fully to the body tube. There is always a small gap, which I think should not be there. I can touch the O ring with my nails in the gap. Actually I thought the body tube was too long, but after ordering an Astrolux S1 which has an even bigger gap, the culprit must be the tail cap incorrectly machined. It is even worse on the Astrolux, which interestingly has a slightly different machining at the end of the body tube, and a smoother anodisation.

Did anyone notice something similar?

Or Keeppower 2900 mAh 18650 protected. It’s protection circuit is designed to step in not under about 10 amps.

Is the PCB retaining ring completely screwed in?

I think it is, can’t move it easily.

Can you show a picture of the inside of the tailcap?
Did you try different cells? Perhaps the used one is too long.

Thanks for looking into this.

First one is the A6, second is the Astrolux S1: http://imgur.com/a/2Jdf9 (sorry for the crappy pics)
Actually, the rubber switch of the S1 protrudes a little from the button guards. Maybe it is overtightened.
I am using Samsung 30Q flattops, they are standard size AFAIK.

The pictures look ok, I checked the tailcap of my Astrolux (don’t own the Blf A6) and even after loosening the retainer ring the tube fits - my retainer ring has a smaller diameter than the inside of the tube. But what I see in your first picture: the knurling of tailcap and tube looks different, with my Astrolux it’s the same. Are you sure the parts belong together?

Did you try to turn the tube by 180 degrees (clip end of the tube to the head of the light)?

Good question. Never noticed the different knurling, as it is not so pronounced in real life than on the photo. But it makes sense as the tail cap has a bit different anodizing than the body tube. I received the light like this. Maybe the tailcap is from a different unit, switched at the factory.

I have one more thing. Does your light have the small ridge between the clip groove and the O ring?