Front facing camera freezes, not working!

Hi,

I keep reading the great solution for the iPhone 4 front facing camera issue after screen replacement, but nothing fo the 4S.

I did a screen replace on a 4S, switching also from white to black. Since then, the front facing camera just won't work. When I switch form the rear camera to the facetime one, i just get a blurred image from what was on the rear camera, but nothing active on the front facing camera.

I read about a small jumper that may have gone missing on the 4 version, but is there a similar jumper on the 4s that could have broken off? All the 4 version photographes are - of course- totally different from what I see on the 4s mobo. I already replaced the camera, but nothing still.

All help is greatly appreciated.