macbook update to snow os x but webcam not working

Here are my best suggestions for your camera problem.

Try each in order until you find the one that solves your trouble:

 • Restart your Mac and check again to see if the camera works now.

 • If not, use your Mac's Disk Utility to repair permissions.

Then check again to see if the camera works now.

 • If not, Apple's http://support.apple.com/kb/HT2090 suggestions may help you.

The proper "reset" suggested there for your Mac sometimes restores normal function.

 • If not, download and apply the latest Combo Update, for your Mac OS.

The current one for OS X 10.6.8 is at http://support.apple.com/kb/DL1399

Repair permissions again immediately following the system restart

that completes the Combo update.

 • If your trouble continues, the problem may be 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.

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."