Attention Electronics Experts: L&M Urban

sms wrote:
On 1/18/2021 6:38 PM, jbeattie wrote:
So, I have this L&M Urban that is probably five or six years old and
well out of warranty. It has gotten a lot of use and recently died in
an odd way -- with sporadic indicator flashes but no light. I tried the
usual protocols for getting it out of safety/sleep mode, but still no light.

I figured the battery had died, so I got a nice replacement 18650 cell,
took the light apart, pulled the battery, carefully removed the solder
tabs holding the protection circuit (spot welded), soldered those on to
the new battery, plugged the tiny lead plug back into the circuit board
-- and the same old problems. Basically I did this:
https://www.youtube.com/watch?v=ZJaI...nel=SamuelEgli

Note that L&M is not doing repairs during COVID -- just offering
discounts on new lights, which is not what I wanted. Anyway, I went to
even greater efforts to remove the little 3/4" square PC board/LED bulb
from the light (no easy feat) to see if anything came unsoldered. There
was nothing obvious.

But poking around one of the little chips (maybe 2mm square with what
looks like four leads under a magnifying glass) -- I got the light to
come on (and about blinded myself). I figured I'd just shorted
something and that it did not indicate something that could be fixed
with a solder, assuming I could get my iron on that tiny little lead. I
have no idea what this little chip does. It is not adjacent to the
power or switch, and I don't know how it fits into the circuit. My
question is would something like this be repairable or is it just junk.
Does making the light come on indicate a problem with a tiny solder, or
is it just shorting around this little controller and that there is a
problem with the chip. Nothing looks loose, and I'm thinking that one
of the tiny chips just died. That light gets super hot.

-- Jay Beattie.

Give up.

Buy the Gaciron V9D-1800. https://gaciron.aliexpress.com/store/2906009.

The thing I really like about this light is that the DRL is not a
strobe, it's "breathe mode." The extra mounting brackets are pretty
inexpensive as well so you can stick one on each bicycle.



Exposure lights have had, pulsed for both front and rears for years. They
also repair, which I do like.

Had my Strada repaired few months back as it has heavy use, as new now.
can’t remember how it is but quite old now!

Roger Merriman