BLF A6 FET+7135 Light Troubleshooting and Mod thread

They replied promptly to my request for a new tube, and I received it last week.

> DBCustom

Chuckle. Hey, I have no objection to “craftsman” one-off creations — that’s art, like you do.

For mass production work, well, that’s where the basic, lowest level skill is turning out interchangeable parts reliably.

Burnsd’s new here, and as you’ve noticed, new folks come in and make the same observations Bugsy36 and the rest of the creative team have heard all too often.

We don’t want to wear down our treasured creative folks, as they’ve done wonders with this light.
They also ended up being teachers about how to do QA and QC. Above and beyond the call. Awesome.

Just saying, this is interesting — Burnsd’s link tells us when interchangeable parts were invented in China (hey, I didn’t know that — did they over there?) Bronze crossbow parts, field-exchangeable. Wow.

What a story that would be if anyone has written it up. And the idea is being reinvented, now, one little shop at a time.

So I applaud everyone for accepting that this round sunk below the threshold for interchangeable parts — and even the cheapest work, maybe especially the cheapest machine tool work — should rise above that threshold.

I want their new trainee machine tool operators — the ones who get assigned to cheap flashlight pieces — to raise the lowest level of skill, and keep improving — so they can make more money, get better jobs, and make things that are much more important than flashlights. Aircraft. Fission plants. Bridges. Trains. Not fall down.

But as I keep saying, I’ve said too much. Again. mmmmmmpfh

I posted this in the other thread.

Thanks THAO916! I’m sorry that in a way I made things more confusing with this thread. Thanks for posting in both!

I’ve been stuck with a DOA BLF A6 since August 24th. I ordered two and one works flawlessly. I was able to take the tail cap from the working light and it makes both lights work. The tail cap from the non-working light will not work on either light. The switch is fine, the contact point is the issue. Neal sent a new tube, which I received yesterday and it didn’t fix the issue. I asked him to send a tail cap to begin with but he said that it was an issue with the tube. The light is still dead…

DJ, send it to me and I’ll fix it for you. Even modify it further if you so desire.

(I can only do this occasionally people, if I were rich I’d offer to fix any that don’t meet your satisfaction, but rich I’m not)

BG just confirmed they will send me a replacement head. I told them there was no need for a entire new head since only the driver is bad, but they insisted.

There is also a small problem with the centering ring being too tall causing it to “turn” the LED when tightening the bezel, but a bit of sanding and a reflow minimized the issue. Meanwhile my A6 remains unused, I’m a bit disappointed since I waited so long and expected a lot from this light, really wanted to see the A6 FW in action.

I’ve been pretty busy lately but I wanted to post that I received another 5a and a bare 3d. I tried to lego the bare with two of my anos to no avail. I didn’t put a caliper to anything but used my knife as a depth guide and the bare tail cap is definitely deeper to the “shelf” that meets up with the tube compared to the others. The bare would have no doubt been a d.o.a. had it been anodized.

I would recommend people first ask for a tailcap and/or new tubes as the tube thread length on mine seem consistent. But not the tailcap depth.

Thanks for all your input thus far my friends!

I guess I’m missing something but it seems to me that it’s less effort to put a few solder blobs on the retaining ring or put a metal shim under the retaining ring to raise it enough to make contact. It’s only a $25 light and if fixing it takes less than 15 minutes then that’s the approach I would take.

I agree. Had mine come in doa -I personally would have. But at the same time I can’t blame people for wanting bg/manker to make it right. I think the idea being that if manker is going to do more business with us (cu/ss lights) they should at the very least test everything that leaves their shop. But in the end…… solder blob/paper clip is way less headache! :wink:

Is there room to add a second retaining ring over top of the first one, to make that contact?
Are the rings a standard size?

I think expecting perfection from a cheap item is unrealistic. Desirable but not usually reality :wink:

Heck I’ve bought many guns that I’ve had to tweak to make work right with the ammo I shoot. And they costed a wee bit more than most flashlights.

I like that idea! But on the tail the tube is really meant to touch the cap outside of the ring. I just looked at one of mine and you’d be lucky to get another ring threaded in but there is one thread showing.

How did you get the head off?

I finally modded my A6 with a triple and bypasses inside both springs. Output (and heat) is really stunning for such a small light.

I get a verry audible whine as well. The higher the current the louder it gets. Retouched all solder points on the board, and it’s also there without the springs and tailcap! Would drowning the whole board in epoxy help to get rid of the sound?

I understand that this is caused by rapidly switching between no current and 10+ Amps.

Summary of my issues.

Basically had problems with bad soldering on 7135 chip. Could not get the head open, maybe mine was glued, I don't know. Contacted banggood general customer service email on 23 September. Got reply on 24th, offered to send me driver only. Declined as I suck at soldering and I can't get the head open, insisted on full head instead. Agreed and head was sent out on 27th September. Today it cleared customs and on the way to me, should receive it sometime next week.

Pretty prompt response I would say... on another note, how do I open up the head?, pliers and elbow grease?, I'm assuming it unscrews at the groove right above the logo.

Is there anything visibly wrong with the driver of my malfunctioning BLF A6 light?

Both wires have dry dry solder joints.
This may not be the cause of your current problem, but it will not be reliable as is.

If you have problems with the low modes, the 7135 chip probably needs to be re-flowed.
(Try to see if the there is solder below the tab on the back of the chip.)

What are the symptoms of the malfunction?

Flashlight won’t turn on at first press of switch, nor second most of the times. When it does, non-click presses scroll through a weird set of modes, with no moonlight but two identical low modes, a mid, and two identical high modes (this is as far as I recall) and the light will eventuality turn off itself.

How to reflow the 7135 chip? Completely de-solder and remove it? I have very basic soldering skills, this is the most advanced stuff I have ever done, but I don’t get any reply from “support” :frowning:

Add some liquid flux at each pin and the tab. Then add a little bit of solder to each pin with a hot (750 F) soldering iron.
The flux will make the solder flow where it needs to go.
Do not spend more than 2-3 seconds per pin with the soldering iron. Do not heat it up so much that comes totally free, allow at least one pin to cool down so the chip stays in place.