Is the USB transfer cable connected?
Cause
The USB transfer cable may not have been correctly connected.
Solution
Reconnect the USB transfer cable or reboot the PC. Connect the USB transfer cable directly to the USB port, not to a USB hub.
Is a USB hub used?
Cause
Electric power from the USB hub may not have been sufficient.
Solution
Use a powered USB hub. Or connect the USB transfer cable directly to the USB port. Also, check if the powered USB hub complies with Universal Serial Bus 1.1 or later.
Does the Device Manager show a question mark "?" Exclamation mark "!"
Cause
The USB driver may not have been installed properly.
Solution
Uninstall and then reinstall the USB driver.
Refer to the following section for the installation method.
T.2.3.2 Is the driver for the USB cable installed?