Convoy BD06 dims and turns off - can it be fixed?

I have a problem with Convoy BD06, when turned on it starts to dim down after few seconds and then turned off completely.

I tried using different batteries and got the same results.
Do you know how to fix this issue?

Does your BD06 use Biscotti firmware (ie. when not configured, the default setting has 5 brightness levels and strobe, bike-flash mode)?

I’m guessing the stepdown might be the flashlight thinks the battery is “low-batt” (low capacity and need to charge).

However sometimes the battery is not really “low-batt”, but the flashlight thinks it is, because of poor contact / connection somewhere (probably in the battery tube).

Would you be able to check if the battery tube is clean and free of grime, dirt. Also check the retaining rings on the tailswitch if it’s loose or any other situation that may cause poor contact?

If everything checks out fine, I suppose, it would then be a driver problem though…

Both guesses are correct!
the stepdown was due to Biscotti low battery behavior, but not because of poor contacts.
R1 resistor was not soldered correctly so I had to re-soldered it.

Thanks for your help :)