text: Built-in Camera Stopped Working on MacBook Pro | MacsPro
  No matter how great Macs are, there is no guarantee a user will not ever face any failures or problems with the system or additional elements.
  One of the additional elements that may fail to function properly is a camera. MacBooks have a built-in camera for your needs. Users often use this tool to have live video chats with their friends and some other purposes. Imagine a situation when it works properly initially, but then stops after working for some time. When you try to launch photo booth or other applications, you see "camera not connected" notification. Are there any good ways to fix this bug?
  Force Your Built-in Camera to Work Again with a Possible Simplest Solution!
  In most cases, it would be as simple to solve the problem as:
  Launch a Terminal utility;
  Enter the given command there – sudo killall
  Right, it is time to get acquainted with the Terminal app and all of its wonderful options.
  Of course, that is not a single solution. Besides, the nature of the problem may be different, so a Mac owner should try all of the listed ideas.
  More Ways to Fix Problems with Mac's Built-in Camera
  Try every option to find the right one for your Apple computer.
  First of all, reboot the system as it helps to solve many different problems.
  Turn to the official Apple company's support.
  Keep in mind that Apple has changed the name of the camera. At first, it was called "iSight." Today, the built-in camera has a name "FaceTime" and "FaceTime HD" depending on the model.
  However, no matter how your built-in camera is displayed, the offered solutions apply to all Mac's built-in cameras.
  Experts recommend testing more than 1 Apple application in more than a single user account. There is no way to try "Guest" as it won't work in this exam. In case you lack user accounts, it is just about time to finally come up with another one. Mac OS X users will find this information helpful: Create a new user account.
  What? Is your camera still misbehaving? A Disk Utility tool is a perfect solution for many similar issues. Launch it to repair permissions of the cam. Next, download and use the most recent Combo Update for the installed operating system. Fix the permissions once more. Stick to the system reboot that finishes the update.
  One more possible solution is using OS X Recovery, which can fix many issues too. It helps to reinstall the chosen operating system and fix many bugs fully.
  In some rare cases, none of the recommended methods may help. It means that a problem is more serious than you think. Just go to the official Apple's website to get a professional support and helping hand. An Apple-Authorized Service Provider will help as well.