What could be the problem with my digital camera?. It cannot start?

The camera went off when shooting a picture with the lense 'hunged') outside, it couldn't go back in, then i bought a new battery, and the lense went back in but cannot take a picture neither start.

try and clean camera battery contacts and try again.

It sounds like you need to warrenty it. If it's too old, it will be too much to fix. Your motor could have gone out, or the firmware copy could be bad.