Q: how to fix "no connected camera" error message on mac os x?

Try these suggestions in order for your camera problem:

(1) Simply restart Mac and check to see if the trouble goes away.

(2) If not, Apple's http://support.apple.com/kb/HT2090

   suggestions may help you.  The proper "reset" suggested there

   often restores normal function.

(3) Use your Mac's Disk Utility to repair permissions and then

   download and apply the latest Combo Update.  For your Mac OS,

   the current one is at: http://support.apple.com/kb/DL1582

Do this even though you already have applied the Mac OS X (10.7.5) update.

Repair permissions again immediately following the system restart

that completes the Combo update.

Properly applying the Combo version of updates can sometimes correct software problems, but, if your trouble is caused by a hardware problem, there are no user serviceable parts of the camera.  For hardware help, contact Apple or an Apple-Authorized Service Provider for service.

(Over time, Apple has changed the built-in camera's name on newer Macs from "iSight" to "FaceTime" and then to "FaceTime HD."  Regardless of the name of your Mac's built-in camera, the same info and troubleshooting applies.)

(4) Unless you have a current backup, make one now.

  Then use the final "Troubleshooting" suggestion:

"... contact Apple or an Apple-Authorized Service Provider for service."