If the camera is like my Canon PowerShot A2000 IS camera, then the battery door could be cracked which prevents the batteries from connecting well and the camera won't turn on even with fresh batteries. If I squeeze the door shut with my fingers, then I can get the camera to work. If I could find a replacement part, I would fix it. I haven't had luck so far finding a replacement part. I also haven't tried a way to hold the cracked battery door fully shut without manually squeezing it with my fingers. I think the battery door was a poor design and this has happened for a lot of people.