You might want to peek into the battery compartment. I have a great gooseneck LED light that just kept on working until one day it was flat dead. On openeing the battery door, I found that one cell had leaked and the termianl was completely corroded to the point of failure. I've tried to repair it unsuccessfully but hate to throw it away. I keep thinking I'll try another time........
Point is: Batteries can still work but leak and ruin a device.