Just for a test you should try taking out the battery for about a minute or so then reinstalling it again, if the camera still doesnt respond try connecting the power adapter and give it another try. Whilst switched off, try also removing the memory stick / compact flash and then whilst still out try the camera again, if by any chance it works reinstall the memory stick and give a further test. If none of these tests make any difference then it really does require further investigation by a service tech.