This brief guide will provide instructions for Mac OS X users on how to resolve their camera issues.
Fixing Camera Issues in a Mac (OS X)
Quit all open apps that may try to use the FaceTime camera
Open Terminal, found in the /Applications/Utilities directory in OS X
Enter the following command strings exactly, then hit return:
sudo killall VDCAssistant
4. Still at the terminal, issue the following command as well:
sudo killall AppleCameraAssistant
5. Enter the administrator password when requested, this is required to execute a command with superuser privileges as prefixed by sudo
6. Relaunch the app that was attempting to use the camera
For more information, please check http://osxdaily.com/2013/12/27/fix-there-is-no-connected-camera-error-mac/ or https://www.youtube.com/watch?v=P-6kTfqn-b8 for a video tutorial.