there's a startup tone, just tells you it has powered up, it's not a warning beep at all, if you have it set to auto restart (default setting) and it has an error initialising the card it will restart over and over so that you would likely notice, that's how people that don't look after their memory cards typically find out there's a problem and contact us wondering why the camera is not working, poor card handling, deleting files ad-hoc, not formatting etc are what most often leads to that behavior, it's not a catch all but it does pickup the most common type of problem, the self inflicted type