Why is my front facing camera not working?

First be sure that the lenses view isn't obstructed by any foreign objects, i.e. fingerprints, dust, etc. Also be sure that the lighting is adequate. If this doesn't help you may need get inside the tablet. When you take it apart be sure that the camera's cable is plugged in all the way; otherwise, replace the camera.

As a last before replacing the camera module, try to do a factory reset. Sometimes, more often than not, there may be a software glitch that will cause the camera module drivers to operate improperly.