There are many types of flashlights now, so new circuitry can sometimes be a problem. However the commonest problem in all kinds of flashlights is oxidisation on the cathode (negative) spring.
There are many reasons to causes for a flashlight to stop working. Such as battery no power, power controller is damaged, etc.
The circuit will stop working once turn off a flashlight.
If it has light, the flashlight is working.
lack of water
broken bulb
put it between the battery and the other contact (both) if u want it to stop permanently just trow it in the water turned on but without the cap -By SciienceFreak
Loose connection or blown sensor !
Bad electrical connections.
Windshield wipers are an important safety feature on cars. They stop working when their motor goes out, or when the blade is too worn out.
the flashlight causes objects to appear larger and easier to see.
It is important to know what causes things to stop working within a car. A blown fuse or bad wiring can cause the key and headlight chime to stop working.
Switch? Relay?
Rat poison makes blood stop clotting and stop working.