BLF A6 FET+7135 Light Troubleshooting and Mod thread

I know this is an A6 thread but I recently bought an Astrolux S41 which if I understand correctly uses the same driver. The light worked fine for a week then all of the sudden it started stepping down through each mode after a few seconds until it shuts off and its as if mode memory turned itself on as well. I figured it was low voltage protection so I tried a fresh cell, same thing. I am using EagleTac 16340 and Soshine 18650 cells. I do not have any unprotected cells to try as I just prefer protected ones for safety. It worked great for a week though on both cells and others have used protected cells with no issues so I doubt thats the problem. Both driver and tailcap switch retaining rings are tight and I also tried bypassing the tailcap completely with the same issues. Any ideas on a fix?

Now the driver in my BLF A6 is stuck in low mode. (wont change modes at all)
Banggood said there were going to send me a new driver, but don’t know when.

Funny, but I have a similar driver issue where there are two dim modes, a bright mode, and what appears to be a turbo mode. Pressing 15+ times the light goes off, then no blinks then after a period comes on in a dim mode. Took driver apart and connections looks good per picture at beginning of this thread. Contacted BG and sent two videos, described here, and they responded with a comment
We are sorry for the inconvenience and I checked the video.But it is not very clear.Can you please check the modes according to this link: ~toykeeper/flashlight-firmware/trunk : contents of ToyKeeper/blf-a6/blf-a6.txt at revision 249 And we suggest you also check the retain ring on the tail cap and head.Make sure the switch could could working normal.
I responded that all is checked, and described the issue again suggesting they show the vids to Neal or heyanquing, and we shall see…

Something in the driver logic is not apparently triggering or the firmware is corrupted.
I have two of these lights that work fine….for the price (now $19) they work amazingly…My hat is off to the designers

Update: They sent a new driver…apparently it takes a bit of discussion, driver installed and back to good again! The new board is apparently a bit smaller diameter and has a tab on one edge to hold it under the brass clamp ring. A little strange, but it works!

I heard when you said shipping back to China was too darned expensive !

Well, at least they are willing to send you a driver. Better luck than I had with Banggood who sent out a new Klarus Mi7 with turbo mode DOA. I FINALLY got another USA based Klarus vendor that offered a new head from their inventory.

Klarus in Europe, or where ever they are, reimbursed them.

Now that ’s warranty service. Banggood NOT so much.

The new replacement driver arrived today from Banggood for my BLF A6, (shipping was quick) and installed the new drover and it works perfectly! :smiley:

Anyone had an issue where each time you enter turbo it blinks then shuts the light off?

I don’t know what did the heat do to the driver but whenever it enters turbo it will blink once then shuts the light off.

Tapping it once will enable the turbo back but it no longer steps down until it drains the battery dry

Mine kinda did stuff like that after I made it a triple. I’m not sure about the stepping down part but high amps seems to mess with the driver. Sorry I’m not much help but at least give a bump to the thread.

Suspect my driver defect now after one year usage.

Very dim light and unable to switch mode.

I tried plug in two 3V battery to see any different. Its bright by around 30 lm.

Guys, do u think its driver or LED defect? As I plan order new driver from BG

:person_facepalming: You have fried the driver

I want to attempt the spring mod but these directions are not clear.
I thought at first I was just soldering a wire from one spring end to the other. After looking into it more, it appears that I’m going to have to remove and resolder the switch and one end of the wire goes on a certain switch arm.
Now I’m very confused.
Does someone have a detailed guide on how to do the spring mod?

I’ll just put this here for comment. It’s been an interesting first couple of weeks with my first BLF A6 XPL. Out of the box, it didn’t work. I noticed the head, fully tightened, didn’t even start to cover the O-ring, and it it rattled. I naively just tightened the threaded retaining ring. It only took 1/16 turn, but the rattle stopped, and it worked!

The head still wasn’t covering the O-ring on the body tube, and the retaining ring had to be tightened every time I unscrewed the head (all 3 times).

So, a few days ago, I finally loosened the retaining ring a half turn and tried to center (it was way off) the driver, and it went down a mm or so. I re-tightened the ring, and it works much better now. Now the O-ring is completely covered, so it’s probably much more waterproof.

I realize that’s a pretty minor issue, but it was frustrating, and I had a hard time getting to like this light. Another reason only enthusiasts and not the average consumer are the target market.

Got a funky driver issue hopefully somebody has had and fixed. Kind of randomly switches back to mode memory. I’ll cycle through and turn mode memory off it will work like it should for a while then all of a sudden boom mode memory. I guess I could live with it but really prefer it to always start low.

The spring has resistance as do the traces on the switch pcb. Your original notion of a wire from the top of the spring to the bottom is one way to do it and very commonly done. Drilling through the switch pcb to bring the wire all the way to the end of the switch that connects to the center pad will reduce the resistance slightly more. All the switch does is connect the outside trace of the switch pcb to the center pad. Don’t overthink it.

The bronze alloy springs have a noticeable resistance
The steel springs have an awful resistance

Best is to bridge those and you eliminated the biggest resistance with an easy fix

Basically you need to pick one or the other. Your first thought is the easier method. Look again at the first post on here and see which one suits you but be aware conneting your switch to the spring takes some electrical knowledge.

Hey guys any suggestions for the driver issue I asked about above? Post #821

Hey guys just got my blf a6 from BG. Seems this latest model has dual tail springs(smaller spring nested inside larger spring). would the bypass still be necessary or helpful? I’m guessing the dual springs helps with current flow. Searched thread and didnt see any mention of dual tail springs.

BTW- what you have created here is one hell of a light ,
When I put in on my shelf the Nitecore EC20 ran and hid behind the 18650’s. :smiley:

Helpful yes, necessary no. It’s only really necessary in cases where there’s already high amp draw like with DD triples that will overheat the springs without this mod. I left mine stock, it gets hot enough that way as it is. If you’re wanting 4A or more then by all means do it, especially with a regulated driver like a stacked 7135 or LD-x.

Sounds like a bad mcu if it won’t hold a program setting. I don’t think any if the external components would affect that but just a guess. Probably need a new driver to fix it.

Hi ,

I searching around for Zener Mod with BLF A6 driver , but I did not find it.Can someone help me ?