My camera smokes when I try to power my camera on.

There are three potential issues that are indicated by the camera smoking.

1 - The battery is gone bad, if you open the battery casing and see white stuff, that is battery acid and you will need to get that stuff out and get a new battery.

2 - The battery port has gone bad, if there isn't battery acid then this might be the case but then you will need to replace the port.

3 - Finally the worst case scenario, the camera has short circuited. This can be cause by multitudes of sources, liquid inside the camera, dust igniting, or over heating. If the short is locatable and isolated to a single component then that component must be replaced otherwise a new camera will be needed.