I have recently purchased a pavilion g6 and i have the following problem.
I connected the laptop to my 23' samsung tv via HDMI so i can watch a movie.
The first thing i noticed is that there was some terrible display quality.
When i "searched" it i saw that the HDMI "tranferred" display data to my tv NOT by my radeon 6470m BUT by intel integrated graphics.
(Of course and i have checked if the gpu is installed)
Check that you have the resolution and refresh rate set to the correct values for the TV. Those will mess up the pictures. I assume this is a laptop, it may be using Intel switchable graphics. There may be an option to switch or it may do it if you set it to high performance.