i have a 4 channel dvr setup with 2 cameras attached , i have been using this for around 6 months with no problems until now, one of the cameras works fine during the day but as it starts to get dark the picture becomes rippled, wavey, how ever the infra red seems to be working fine, and if i unplug the power to the camera and reconnect the pictur is fine for around 10 min. i have tried swapping leads over etc but still the same problem,and as the daylight comes the camera works fine, any advice would be greatly appreciated thanks