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Make sure you are not pressing the Shutter button while turning it On.
Also make sure that you do not have a stuck shutter button... I don't know what age your camera is, but such behavior is more typical of a defective switch than of any setting on the camera
Also... to make sure it is not a setting of any kind, you can do a factory settings reset on the camera. Be warned: this will wipe out all individual settings, such as White Balance types, on the camera... do you want to try that, a factory settings reset? if so, and if you need instructions on how to do so, let me know, and let me know the camera's model # please too.