Your camera could be turning off suddenly during use due to a dying battery or a battery that is malfunctioning. First recharge your battery. If this doesn't fix the problem, replace the battery with a new Sony approved battery.
A few possible reasons your camera won't capture photos are as follows: 1) Your memory card is not inserted correctly. 2) Your memory card is full. 3) Your memory card could be locked. Take your memory card out of the camera and check to see if the small switch on the side of the memory card is on lock. If so, switch it to unlocked.
A few possible reasons the camera won't turn on are as follows: 1) Your battery may not be inserted correctly. 2) Your battery may not be fully charged. 3) Your battery might be defective and will need to be replaced with a Sony approved battery replacement.