Odd problem on just 1 of my BLF A6’s. I know you guys are going to say it’s a physical connection, contacts need cleaning; I don’t think so:
After not using the light for several hours, it refuses to turn on using the switch.
If I remove the tailcap and put it back on, it starts working again. Alternately, apparently if I remove the head (vs the tailcap) and put it back on, then it starts working again too.
After that, it will work reliably until I put it away for a few hours. After it sits a few hours, this problem happens again. I’ve now witnessed this many times.
It doesn’t appear to be the switch, because the switch works once the driver seems to be ‘reset’. Which makes no sense, as this light doesn’t use a soft switch. It then works fine, until it sits for several hours. This happens reliably. If it were the switch, I’d see the same problems whether it sat around or not. But it only happens after sitting for several hours.
I’ve changed batteries, both charged and unprotected Panasonic and Samsung 30Q’s.
Are both retainer rings firmly tightened (in clockwise direction)? And is there still some play in the driver board or in the tailspring board? And I mean play in the way that the board(s) can slide laterally under the retainer ring(s).
If that is the case, the driver board and/or the washer between the actual switch and the tailcap cover are too thin.
I’m thinking loose driver board. In use heat expands the body, board moves slighty. When it cools, the board doesn’t move back into contact till pressure from the cell on the spring varies by opening the light. Driver area sees more heating than the switch area so most likely there. Mine was from the second batch made and both retainers needed tightening out of the box.
Here’s an update. The situation worsened. Last night I came in my room, and the light had come on on its own. (I guess I had left the hard swith in the ‘on’ position after giving up.) Luckily, I had disabled Memory mode so it was on Moon mode.
The problem is in the head. (I shorted the battery end to the tube—nothing.) Basically, the light won’t come on at all.
I then lego’d the head to a known working, non-anodized A6 body/switch (with its own good battery). The head still would not come on.
I checked the head’s retaining ring. It’s on really tight, it’s not budging, and I haven’t tried to force it yet. The board does not wobble. I ran a rag inside to clean, no help.
I did notice that the inside of the head is FULLY ANODIZED (all the threads, and the back end of the head tube). I don’t see a way electricity could transmit from the battery tube, except perhaps by way of the retaining ring somehow (even then, not sure)? Are those head threads supposed to be anodized?
Related misadventure: the prior night, while troubleshooting (it wouldn’t come on), then came on by itself after a few seconds, in “less than moon mode”. It was so faint, I held the LED up to my eye to see if it was really on. Unfortunately, the light then, on its own, CAME ON TURBO right when it was 2 inches from my eye. Luckily, the reflector was off. But I saw a spot for 15 minutes. And for the first time playing with flashlights (including intentional eye-shining), I worried that I might have permanently damaged my vision. (Vision seems okay now though—I hope.)
Similar thing happened to me with my Thrunite TN4A. I wanted to check the moonlight mode, so I held the light in front of my face and then long pressed the side switch to turn on moonlight. However, due to the way I was holding the light or something, my finger slipped just enough so that it lost its grip on the switch slightly, and the switch registered a double press. Bam, instant turbo, instant fried eyeballs for a good 20 minutes.