BLF A6 FET+7135 Light Troubleshooting and Mod thread

Don’t bother counting 15 clicks out, power it on and just half press it until it stops getting brighter.

From memory you have to start the quick presses from low mode and moonlight was only on the seven modes. Keep pressing quickly until the light stops responding to your presses.

On further reflection,I might have damaged the driver with over voltage, I was testing with a power supply, and a battery, and instead of using a multimeter on Amps, I accidentally added 4V from the power supply to the back of the battery… :person_facepalming: the bond wires on the led blew, but I am lucky enough to have those fixed at work :smiley: So, I fixed the led, but maybe the driver was damaged in some way with the 8 V I combined whenI added the power supply to the battery.

It’s just the moonlight I miss really, as I still have at least 4 modes, with the quick access to Turbo….

Thanks for the inputs

If you’ve still got modes its still working.
Does this light have a lighted tail cap?

The modes were doing really weird things on one my lights after I did a spring bypass. I reflashed the driver and that fixed the issues. If you have the know-how perhaps you should consider doing that.

No lighted tail cap that I am aware of. I put the driver in my old BLF Eagle Eye X6.

No, I don’t re flash drivers, that’s just creepy/weird :laughing:

But it definitely has no moonlight now, I can’t get to the 7 modes or the configure modes, and the battery checker doesn’t blink, it just stays low( But I know it’s the battery checker mode, because it has the strobe before, and the bike flasher after…)

Cheers

Sounds like maybe the 7135 chip died, which would also cause the battery check mode and config mode to not look like they work. The amc7135 chips don’t respond well to excess voltage, even if other components survive.

I see. how do AMC7135 chips usually die? Aside from over-voltage? How about over-current? or other scenarios?

Usually just from excess voltage, which makes them overheat and burn out. Afterward they usually stop responding to the MCU and let a constant amount of current leak through. This would make all the 7135-only blinky modes stop blinking, and would make moon and other 7135-only levels all look the same.

Anybody know where I can get a new reflector? I had a little accident with mine :person_facepalming: I’m currently using a smooth S2+ one but it doesn’t have a groove for the oring.

I’ve killed more with excess heat [during soldering] than any other way.

I ONLY reflow 7135’s now, not that you can’t still overheat them but I find I have a whole heck of a lot lower failure rate with hot air then I ever did with an iron.

Is there a way to test the 7135 is ok, say with a multimeter? I suspect mine may have also gone as it appears to be stuck in the highest 4 brightest modes and I can’t cycle to the config menu.

You didn’t try to put a lighted tail cap in it did you? I know that will cause that problem if a bleeder resistor isn’t used when installing the lighted cap.

Nope, everything as standard. I believe the lighted tailcap issue is that mode memory won’t work correctly, i.e. mode memory will be on even if set to off.

I see. I think this thread is what you are looking for.

Thanks, I’ll take a look.

Are there holes in the UI? In lower modes the FET isn’t on at all so if the 7135 has gone bad there will be modes (moon & lower modes) where there’s zero light output. If that’s not the case it’s probably not the 7135 being bad…

Anuway to test the 7135 you jumper the right pin to Vcc, this will make the 7135 turn in full (0.35A) which you can measure to confirm its good.

If I recall correctly, the 7135 chip tends to fail in a way which passes current, so it would have the same brightness regardless of the PWM signal sent to it. If the lowest few modes are all the same, that may be what happened.

No holes in the UI. Essentially the light has 4 modes consisting of the brightest 4 modes of the 7 mode group (compared against my other A6).

Thanks for the info on testing the 7135, I’ll take a look when I’m back home.

Would a failed 7135 prevent access to the config menu?

There must be multiple failure modes possible then cause I’ve had more than my share of them suffer heat related deaths in which they have zero output. The only time I’ve had them fail in a way which causes them to stick open is in over voltage scenarios (2s builds).