iMac camera
I purchased a used iMac running High Sierra. FaceTime does not show my picture and Photo Booth does not show a picture from the camera. Photo Booth also does not show up at the bottom of the screen.
I agree with Mal-S. You should follow the steps in the article linked, but if you follow those steps and the camera still won't work, try resetting the SMC of your iMac. It's easy- just shut down your iMac, then unplug the power cord. Wait 15 seconds, then plug the power cord back in. Then, wait 5 more seconds, then press the power button to turn on your Mac.
Beyond that, it's probably a hardware issue, then. You should take it in for service - Find Locations - Apple
