R1 and R2 make a voltage divider
R1 1k connectoed to batt+
R1 and R2 on MCU pin 7 Off detection about 3V when battery full
R2 3.3k grounded
It happened some time MCU voltage got grounden by accident, then R5 4.7Ohm burns like a fuse
Thanks Lexel, should I resolder or change some component in this case? I want to make this driver working.
first would be measuring if on MCU pin7 are 3V, if not the voltage divider is not OK
checking if the MCU gets power between the diode and C2
as the MCU pins are bent 90° the contact area to the pad is very small might be solder problem there
I got no reading :(, this has to be faulty. May I ask you, could you send me a new one 17mm Bistro HD OTSM (Tail clicky lights) driver together with my Buck driver order?
on the black one the common point on the resistors is very close to copper ring, if there is a short you get 0V reading or if R2 is shorted
the white version is improved in tiny details
Yes, R2 was grounded to the ring. So I removed it, wicked off all the solder and found, that the pad of R2 is conected to the ring. There is no way how solve this I guess, look below
It looks like there is still a layer of solder. Are you using solder wick?
If you can get to the clean pad material you can try taking an exacto knife or similar and break the connection.
those are possible short areas
also under R2 a short may happen but less likely
Its no problem to make a replacement for a fee that covers shipping parts and the time to make it,
usually cheaper than failure analysis but I try never to scrap a driver that has an error
I test all drivers here befre shipping so I have some that need fix and often points on little design errors (or fab errors because they are not within 6 mil with a layer)
on latest Gen I used 8 or 10 mil safety distance
Okay Lexel, I will check once more the spots you showed as potencial issue, thanks 
Lost a switch pad on my skilhunt driver. Anyone know another option?
You can use one of lexels switch boards from oshpark as a replacement.
Is there another option to connect the switch?
ATiny 13/85 try the #2 Leg of the MCU the other to Grnd.
Awesome. Thank you very much. I know there should be a pin from MCU.
Now I need to figure out were number 2 is.
Thank you and Merry Xmas
Number one marked with a dot on the atmel. Pin 2 is in the same leg line next to it.
Thanks for the save 
I been in a rush to get this together before family shows up. Doesn’t pay to hurry, I know.
I guess pin 2 is what Lexel uses on that driver? It can certainly vary. It might be best to trace the circuit back to verify it’s pin 2. (I’ve seen drivers where pin 7 is used)
Alternatively, you can scrape the solder mask off the trace by the pad and attach the wire there. The current is super low for the switch.
What BLF based/designed drivers use pin #7?
Every BLF based driver using the Atiny13/85 I have used, uses #2 Lexels/RMM’s.
Your welcome, Merry Christmas to you and yours! 