BLF A6 FET+7135 Light Troubleshooting and Mod thread

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 ?

Same as any other linear driver I think. Replace D1 with 200 ohm resistor and stack Zener on C1. To keep low voltage detection you need to change the R1/R2 voltage divider. I think it’s somewhere around 20-22k for R2.

I made zener mod on 105c driver. I’ve got 5.6a on MT-G2 led , but after 10 seconds 7135 chips overheated and current drops down to 3.3a - this is termal throttling.

Will I have the same problem with BLF A6 driver ?

No, the FET doesn’t limit the current so there’s no heat. Current is determined by battery voltage and led Vf. At least according to the 7135 data sheets they can handle up to 2V over Vf but practically speaking it’s much less. To achieve more requires more heat sinking dedicated to the 7135’s, a lot more.

if you want run higher currents through 7135 you need to pot the driver with a heat conducting material
also has the positive that the driver is better protected against recoil and impact

another crazy way to cool the driver

he sold this light this week and wanted only 90$ for it crazy on CPF I bet some people would have paid 300$ or more

On 105c driver I made Zener mode with LVP like this way

I’ll think on BLF A6 must be like this way , Right ?

Can someone tell me why there are pin3 solder pads on the spring side of the driver???

Does anyone know where I could buy a replacement switch (not switch cover) for my
BLF A6/ Astrolux S1? Or if not that do you know where I can get another equivalent that would still work in the light. I allowed the internal plastic pieces to get too hot during a spring bypass. In my defense it was my first attempt at a spring bypass of any kind. Why oh why did I not practice on a pos light first. The switch works about 3/4s of the time because I only damaged on section but it is still super annoying especially since I love this light as my EDC. Any help would be truly appreciated. I have learned so much on this site, learned and acquired yet another addiction (fishing, knives and sharpeners, ecig mods, and now led flashlights)
-Joey

premounted on board
switch

Thanks a lot SigShooter I really appreciate it