dead convoy v2 driver / dead attiny13 after drop

Driver of my S2+ (SST20 version, 8x7135 from BG Convoy s2+ sst20 4000k for $10.99) died, possibly after drop, idk if it was this one or another as nothing seemed weird or broken initially after dropping it. Then a few days ago, low output despite full battery, then after a few clicks nothing, no output at all. Switch, LED still functional, got to be the driver.

Tested low voltage on output side, ~ 0.4V *. I’m assuming dead 7135s wouldn’t cause low voltage as they’re current regulators and unlikely to fail all 8 simultaneously, so it’s got to be the ATtiny13, the capacitor or something internal in the PCB.

*Actually I just measured it again, not 0.4V but 2V then fairly quick, 10s or so, ramp down to 0V.
What is the cause for this kind of failure mode?
Would reflowing the ATtiny13 help?

I drop my S2+’s all the time and they show very similar symptoms. Nothing appears broken, but the lights all flicker, switch themselves off/on, and are at time no longer controllable. I normally disassemble the light and put them back together. Or clean the threads. On a different light I reflashed the ATtiny. Regardless of what I do, the lights appeared broken for the foreseeable future.

(Having said all of the above, my S2+s are not necessarily the most reliable lights when it comes to the flicker issue. The kind of all have this problem after a few months of use).

The one thing I have never tried (but should), is replacing the springs which probably took the brunt force of the impact.

Try tightening the pill's and the switch's rings it may solve many issues :)

Damn, I thought these lights were relatively tough. Vaguely remember a video where they were held in boiling water or thrown against a wall. I’ll try reflowing. Don’t think its the spring but I’ll try that too.
Btw I have another, older S2+ with a standard XML2 that still works without issue. DK if the driver is identical, it’s 6x iirc.


The switch is operational and the pill has no ring, it’s soldered (was). I’ve got a battery connected to the driver directly for measurements.

All my S2+ flicker to an extent, with or without any drops. sometimes a good cleaning helps, but most of the time after a while, like 6-12 months of usage, they just start flickering. It also appears related to temperature, more flickering outside in the cold.
Not sure what to do, maybe the threads or anodization are worn out. I agree the springs look ok, might change them anyway

Flickering is often an indicator that the retaining ring is not tight enough.

Yes, very valid point. tried all of that, cleaned threads, rings are tight, all solder joints are good, etc. still flickers from time to time… I am running a TA 17mm driver, if that helps. But all of this got worse after the various drops…

The retaining rings should be screwed in VERY TIGHT.
I have had those issues with several S2+ es, usually things just need to be tightened.

The tail cap must be tight.