jimer337

I have a pc with a dvr card installed which i use for personal cctv, up until recently i have been using 3 B&W CMOS cameras, 2 of the cameras i thought packed up cos all i would get is like snow interference on the video software program but 1 still worked. So i thought i would change all of them to Colour CMOS cameras so i bought 3 installed them and guess what the same but now all 3 do the same "snow interference". If the PC is cold (left for about 30 mins) when the pc starts the cameras will work for about 3 mins before the snow comes back, so i changed the PC to another one (just in case of temperature problems) but still the same, so i changed the DVR card 3 times 2 of the same make and 1 of a different make, guess what STILL THE SAME!!!!! But the one B&W camera i had that worked still works?????? I am stumped i have run out of ideas to try. Any ideas would be greatly apprieciated. James