hippiejoe

HD-CVI is intended to produce 1080p or 720p over existing coaxial or Siamese cable. From my reading you should never use Cat5e with CVI as the signal decreases drasmatically the further out you go. If I had Cat5e, I would opt for IP cameras and an NVR. If you are already committed down that path, just run a good quality coax that is all copper and no aluminum parts.

I have about 25 Dahua Hybrid DVRs that I have installed over the past 2 years. I have been seeing problems with the small fans on the motherboards. Most of them have 3 heat sinks with 5v fans mounted in the heat sinks. Fan attached to heat heatsink with 3 screws. The heat sinks are 55mm which is the mounting screw distance. I can't find any information on replacement fans or better ways to keep these cooled. I never installed case fans. I have lost 2 DVRs in the last year and think it was due to a fan not turning. I found a 55mm heat sink and fan combo, but the fan is 12v. The 5v pins are not enough to start the fan up every time. So I need to tap off of unused hard drive power leads. It is labor intensive because mobo must be taken out to remove old heat sink. Compounding the problem, my DVRs are spread across the US. So I can't easily do this upgrade. I would really like to find a replacement fan that can be installed with the 3 screws to the existing heat sink. Dahua forum and my suppliers have not been able to help me. Anybody help out with this before I start losing more DVRs? Thanks, HippieJoe