parking sensors & back-up cam not working
 

When I put it in reverse, there is a constant beep and the screen does not switch to camera, and the button to manually turn on parking assist blinks rapidly. I put my ears to the sensors and they are not working (all of them). So it think the problem may be more "central". Any ideas?

2010 Q5 Premium

Note: recently I transported some furniture where I had to leave the hatch open and the lid slammed down on the furniture a couple of times. However, I think the problem did not start exactly at that time. If the camera was broken, would the whole system act like it does?

Thanks!