CJ04

It is strange alright, but I'm grateful for everyone that suggested options, it is a good community. q-see power supplies, rated at 12Vdc 200mA (tried 2 on same wire run) is 18V at both ends. Another power supply, rated 12Vdc 400mA, actually gives 12Vdc. CJ

Have you tested the cameras again with a local power supply after you tried reversing the polarity. Are those cameras reverse polarity protected, if there not they could be damaged now. Kensplace, I would doubt they have any sort of protection, they are low budget q-see. But in answer to your question, yes cameras are still working and using those same power supplies.

Thanks for keeping contact on this issue. I've measured voltages at power supply and camera ends, with and without load (camera) and the result is the about the same. I've several power supplies, tested & working with other cameras, and the result is the same. The only way I get video on the DVR is when I connect the power supply (any of the ones I have) directly at the camera location, hence bypassing the power wire-run. I'm about to give up and run a cable to the garage, not easy, but is the nearest power source. Any last thoughts ? Anyone..

A suitable place. I've always wanted to "clean up" our IT Department!

Thanks for your input, I'll test it as soon as I get home later today and post the results. If I understand what you're saying, without the camera there is no closed circuit, therefore no current and hence no voltage drop. If so, there would be a voltage divider between the cable resistance and the camera. Increasing the voltage source, assuming cable load is not very big, should help bring the voltage back to operating parameters, although power consumption won't be close to optimal. CJ.

Thanks scorpion. Actually I have video in the DVR (located in the IT/Washer/Dryer room) when I put power directly into the camera, by way of several extension cords. So I know video is fine. Could it be possible to have the cable stapled against an aluminum stud affecting the ground connection ? while still having the DC voltage correct at the camera end.

Thanks Soundy. Yes I am sure, tip is positive, shield is ground and polarity is verified with my voltmeter. Although I must confess I also tried reversing polarity to check, with the same results (power supply still works ) I have the same DC level and polarity in my connection to the camera as I have in the IT room where the power supply is.

Thanks zmxtech, done that. In fact I have good video if I use the power supply connected directly to the camera (by using several extension cords).

I've been interested in this topic and finally decided to give it a try at home. This is my first installation and a low budget one. I thought the DVR programming and Internet monitoring would be the greatest challenge but it turned out working fast. The problem actually lies with powering the cameras and here I'll appreciate any guidance. This same problem occurs in two different camera locations at home. After doing the cutting/cramping & soldering of the camera pwr supply barrel connector I measure the voltage correct at both ends of the wire, but the camera (tested) does not work. I have two pairs on each run and I have also tried unsuccessfully to use them combined, I realize there is a voltage drop but distance is less than 50 feet and related charts I've seen do not show any major drop. Any suggestions ? TIA. AVR761 Model 4 2xQ-see 30ft night / Color Sony Sensor 12VDC 200mA 1xQ-see 100ft night / vision Sony Sensor 12VDC 1.5A