Astrolux S41S - no light in Moon mode & Battcheck mode, driver problem?

Got this Astrolux S41S (quad-Nichia 219C) to check out, I think it may be a driver problem?

Normally, it uses the BLF A6 driver, which defaults to 7 brightness levels:


In this particular Astrolux S41S,

clicking once to Moon will have no light at all (I think I got 0.002A -- maybe that's too low to power up the quad-Nichia?)

the next press (Low) has light,

another press goes to Med1, but Low and Med1 are the exact same brightness (I also double-checked with the tailcap current, same current)

Med2-High1-High2-Turbo seems to function normally though.

So, the problem is:

  • no light output in Lowest (Moon) mode
  • the 2nd & 3rd brightness levels are exactly the same brightness

Then the special modes,

so from "Moon" (where there's no light), a long-press goes to Turbo (OK), then another long-press goes to Strobe (OK), and another long-press goes to BattCheck mode.

The BattCheck mode does not output any light at all (note: the battery is freshly charged), then another long press goes to Bike Flash (OK).

So, the other problem is that BattCheck does not light up.

Then the Configuration mode:

I half-pressed many times to go to the BLF A6 configuration mode (it should "buzz", like in an Astrolux S1 which I also own).

There's no "buzz" and no light at all.

So 3 problems with this Astrolux S41S. Any idea what might be the problem? Driver issue?