First of all I would recommend loading the default settings in BIOS. Save these settings, exit the BIOS and restart your notebook.
Then make sure that the newest webcam driver from Toshiba is installed. You can download it on the Toshiba website.
Furthermore it would be recommendable installing the newest BIOS version. Check the Toshiba page!!!
In worst case if you get the same problem after reinstalling from Toshiba recovery disk it’s hardware related. That means you should contact an authorized service provider. The guys can check the notebook and exchange the hardware (webcam, cable or something else). Just get in contact with the guys and ask for help. From my own experience I can say they always try to help you as best as possible.