I'm quite a new OS X user and come from a linux background - usually to debug my problems I consult the logs as per /var/log/syslog however with Yosemite i'm not sure what i'm looking for.

Any way my problem is that I will load Skype and video call someone which works fine but the moment my mac is locked or goes into hibernation mode the next time I try video call the web cam is not detected - if i attempt to use Photo Booth this too doesn't detect a webcam. Some google searches has revealed it's a conflict where the camera is "in use" when it isn't - and other articles seem to point towards AirParrot which i do not have installed.

  1. How would I determine where the fault is?
  2. How do I then resolve this fault?

Rebooting does seem to be a solution but IMO theres a bug that needs fixing because rebooting to get a cam to work is just simply absurd - even Windows can function more reliably.

  • 3
    When this happens, open Terminal and run sudo killall VDCAssistant. I have an issue with my webcam as well where moving the screen will disconnect the camera... Killing VDCAssistant fixes my issue sometimes.
    – aglasser
    Dec 14, 2014 at 21:37
  • Legend - thanks for the quick reply works a charm. I would never have known how to do this :P
    – Ash
    Dec 14, 2014 at 21:39
  • See my answer here stackoverflow.com/a/45861186/825364 Aug 24, 2017 at 12:08

2 Answers 2


As commented by @aglasser to fix the Cam not working simply:

  • Open Terminal.app; and
  • Run: sudo killall VDCAssistant

In order to resolve another similar issue with the built-in Microphone:

  • Open Terminal.app; and
  • Run: sudo killall coreaudio

Running disk utility and reinstalling the O/S are probably not the best first things to do.Except you can run disk utility (/Applications/Utilities) and select your Mac HD and click on repair permissions. That will work while you are logged on and started from your main startup volume. Permissions can get munged and doing this is usually quick, easy and a decent first step.

Logs can all be found by running the console.app in /Applications/Utilities. Being a linux guy you are probably well on your way once you've found the logs.

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