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.
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
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.
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.
Anything that brings the car to a complete stop? Such as the brakes or a Tree?
Rat poison makes blood stop clotting and stop working.
Switch? Relay?
When you turn off a flashlight, you break the electrical circuit that powers the light bulb. This stops the flow of electricity and causes the filament in the light bulb to stop glowing, thereby turning off the light.