Can lenses be swapped ?

Thank you so much for your rapid answer to my question. It was not what I wanted to hear but if all my questions were answered to please me, it would be a dull world !!! I was the Distruct Manager for Bell & Howell from 1967 to 1974. B & H was the Distributor of the Canon line of cameras during that time. I covered Washington, Oregon, Idaho, Alaska and Montana for them. I fell complely in love with the Canon line. The last Canon I introduced was the Canon F1 System. At that time this system was far and away better than, in my opinion, any other photographic sytem available. Anyhow, thanks again for your help. Oh, yes, I still use a Canon FT with a 55mm f1.2 lens for my Black and White pictures. At f1.4 the resolution is unbeleivable. Phil Chapple Thank you so much for your rapid answer to my question. It was not what I wanted to hear but if all my questions were answered to please me, it would be a dull world !!! I was the Distruct Manager for Bell & Howell from 1967 to 1974. B & H was the Distributor of the Canon line of cameras during that time. I covered Washington, Oregon, Idaho, Alaska and Montana for them. I fell complely in love with the Canon line. The last Canon I introduced was the Canon F1 System. At that time this system was far and away better than, in my opinion, any other photographic sytem available. Anyhow, thanks again for your help. Oh, yes, I still use a Canon FT with a 55mm f1.2 lens for my Black and White pictures. At f1.4 the resolution is unbeleivable. Phil Chapple

the menu screen works but there is no image from the lens. I tried swapping the CCD with another lens unit but it is also black the menu screen works but there is no image from the lens. I tried swapping the CCD with another lens unit but it is also black