Good job @outwalking, it is important to separate the operation of a circuit in parts and review it from one end to another to determine the problem. Now, could you solve it?
Usually the mechanical buttons are damaged after time of use, it could be that at some point the button stops performing its function, which prevents the continuity of the circuit and resets to standby mode. This is a commitment, I have never had the opportunity to use one of those flashlights and I do not know its possible faults.
Thanks for your response. I this case don't think the switch is the problem but in a lot of cases, it is the switch because it is the only mechanical component. This flashlight is such a low cost item that I really doubt they would have put any addition circuitry in it. On higher cost units you could be correct. I did a little more digging and I think there are some micro transistors that they are using as switches that may have failed. I am removing the circuit board so I can draw a schematic some I can better trace the circuit. That's why I didn't show a repair in the post.
Ohhh ok. Well, if you could share the scheme of the circuit, I would like to take a look, I am interested in the operation and I want to understand it in a circuital way. :D Thanks for sharing.
I will. As soon as I can get it done, I will post. Thank you for reply.
I probably won't have time to work on this for a few days. So I found a link that gives some schematics for a similar light. Hope this helps.
http://www.instructables.com/id/Shake-Flashlight-1/