If you are getting black pictures, your strobe did not fire as it may have been set off by the preflash or somedoby else's flash. You need to install the magnet to prevent the preflash firing
Test your flash at home by setting it in front and to one side of your camera, and shoot a picture, the housing and cable are not necessary, just use the Inon's sensor to detect the camera's flash. Set yourcamera so it always flashes.
You can test your fiber optic cable by shining a light at one end and looking at the other end. The red rubber cap is fine, all it does is keep outside light from the photosensor
The secret is to test everything at home, dry, to make sure all is working and well coordinated. Good luck!
