techwell

hi, i just installed a 4 CCTV cameras in my store and its working fine during day. But a few seconds after i switch off the lights at night the images starts blinking(on n off) for some time or a horizontal light appears in the screen or vertical colored lines appear randomly. Sometimes the images can be seen steady but not clearly. The problem is only with night vision of my IR cameras. What could be reason. Is it coz of faulty installation or any hardware issue. Please suggest.

It was initially connected to UPS but then i tried with direct AC supply. But the problem persists.

Hi, As i told you i had changed the power supply and now the coloured lines have stopped but the night vision is clear only when i connect two cameras. But when i connect more than two 1 or 2 cameras will give me clear picture where as the other two will have a blurred picture. Also sometimes the picture keeps switching on and off. Now i have read in this forum that it is because of power supply. But i have used the same power supply elsewhere with 4 cameras and it is working fine. Why not here. As i told you the longest cable is 15mtrs.

sorry for posting twice. i am a beginner in CCTV installations and can give only a few details right now. Using 1/3" Sony CCD 32 IR Cameras with CP PLUS 4 channel DVR. The cameras are powered by a single power supply. Somehow i guessed the problem to be with the power supply and have just changed it. Can only know the result in the morning. And the maximum distance of the cameras form the power supply is 15mtrs. Thanks.