On 22/03/2016 05:56, DaveC wrote:
I beg to differ with your diagnosis. Unless the LED has magically
turned into a thermostat controlled flasher, it's not going to do
that. More likely, the LED driver circuit is doing the flashing.
Based on zero detail about the actual flashlight, my wild guess(tm)
would be the big electrolytic that usually goes across the battery.
Broken or badly soldered connections on the driver PCB are also
likely.

Nebo NU15J:

https://www.nebotools.com/prod_detai...=94&subsubcid=

I like this model for its good trade-off between brightness and battery life.
Might be €œbetter€�, but this fits my needs. (And it ft fits in my pocket
along with my micro Swiss army knife...)

No controller chip. Looks like a boost converter (inductor, BJT, schottky
diode, ceramic cap).

I scoped the voltage across the LED: it's constant 4v (with a very
small--20mv?--rise and fall as it switches on and off). Havent yet
measured current. Surely if there was a bad solder joint or other failure it
would show up here.

Thanks for the referrals of other lights, but Im not buying a replacement.
Im doing this for fun and to learn.

Cheers.


Desolder the original LED, carefully , as balance of probability it will
be fine.
Jumper in any old high power LED and see if that flashes too.