If your input video signal(s) are not very strong, the V-4 may have difficulty properly stripping the important sync signals from the video. This can result in poor video output, unlocked video output or a black-and-white (no color) output. In order to verify that the V-4 is working OK, try inputting a known strong video signal (such as DVD player) directly into a V-4 input, using a known good short length video cable. Then check the V-4's output by using a known good short length video cable to view the V-4's output on a known good standard TV set. A good V-4 will show normal video. If your video looks good in this test but black and white or noisy in your setup, you'll need to look more closely at your video sources, your video display and the cabling involved. Long cable lengths can cause such problems. You may need to upgrade your cabling or employ a Distribution Amplifier at your video source.