Make sure you have good batteries in the camera. Check to see if there is corrosion in the battery compartment. If there is corrosion, you must clean it out and clean the contacts so they shine. It sounds like either low batteries or a bad connection. It could also be a defective switch, though I doubt that is the cause. Leaving batteries in a device that is unused for a long time will usually result in corrosion. If this is a point and shoot and it has corrosion in it, if you are brave enough to try it, after the large corrosion pieces are removed try using a Q-tip dipped into vinegar to wipe away the rest. After doing that, Use another Q-tip dipped into a cup of water with a teaspoon of baking soda dissolved in it. That will arrest the acid in the vinegar. If it is a SLR and it is corroded, take it to a camera repair shop. That type of camera is too expensive to try to clean yourself. Good luck.