It is possible that your USB cable is not working, so you should try using a different cable. If that doesn’t work, try connecting your camera to a different computer. It is also possible that there is a problem with the camera software on the computer, so you should try uninstalling and reinstalling the software onto your computer. If that doesn’t work, try using a different USB port on your computer. If none of the above works, you should clean out the USB port. Also, remember to make sure you are using the right kind of cable.
It is possible that your hard drive cannot read the SD card that you have inserted into the camera, so you should try inserting a different SD card. If your camera does not recognize that SD card, it is possible that the SD card port is damaged in some way (most likely water damage), and needs to be replaced. It is also possible that your hard drive is malfunctioning and needs to be replaced. Finally, it is also possible that the software that reads the SD card is not working for some reason, and you should take your camera to a professional to have it looked at.
It is possible that your camera’s battery is dead, and your first step to troubleshooting your camera should be to charge the battery. Next step would be to connect your camera to a computer to see if other camera functions are working properly. Next step would be to check the flex cable of the device. For instructions on accessing the flex cable, reference the repair guide for this device.