GE Television Dark Shadows. My television is really dark. Commercials are usually viewed fine if

Question

My television is really dark. Commercials are usually viewed fine if there are a lot of colors, but during programs, faces are extremely dark almost black and the background is black. Please help. The television was given to me by a friend who told me of the problem, but I didn't realize how bad it was until we hooked it up. She said they had a repair man come and fix the power button and shortley thereafter the dark shadows appeared. Again, please help!

AM