How to fix Olympus Tough TG620 will not take photographs

The power button causes the screen to flash but will not turn on the camera. The play button turns on the camera but will only allow viewing images from the memory card. I cannot take photographs. But I can see all the menu options, set the clock, zoom images from the card etc. The battery is OK. It charges via the Olympus power cable and from a PC so I do not think the battery is an issue. Everything seems to work except taking photographs. Pressing the photo button does nothing. Pressing the power button makes the screen flash. Pressing the ? button shows the current date and time. Re setting the camera to factory settings does not help. What is the problem and possible solutions?