cctv problems

mazthespark

Hi all,
having a few problems with particular cameras in place i do some work. most of them work fine but a few are still causing problems and have a few questions
1. can rg59 be affected by electrical interference i have tested the cable and camera has power but still no go?
2. some of cameras have a 6 core alarm cable ran to them for power cores doubled up etc. i get 12v across the cable with a multimeter but could it be a low power problem as to why it wont work.
have tried other cameras in some of these locations to take that out of the problem but stillno joy
3. 1 of the cameras is a bit hit and miss works for a while then goes again.

Any suggestions?
Thanks

indie armada

providing the coax doesnt have too long of a run i would do a continuity test on the coax and on the psu cable. try bringing a remote psu and a test screen to the site of the camera to help eliminate the fault

mazthespark

Ya I made up a test kit with a screen and internal battery for powering screen and camera independent of system so will give it a try next time I am working there

Jnealon

1) Connect the camera using a short lead to a test monitor to rule out the cable
2) Did you get the 12v when the camera was on load or disconnected.
3) same as one buy check all connections, check the psu, check the DVR log for times for when the signal was lost and see if it corresponds to anything else going on line heavy machinery running etc

Depending on what kind of tools you have see if you can measure the output of the camera, you should be getting 1vpp.

mazthespark

Jnealon wrote: »

1) Connect the camera using a short lead to a test monitor to rule out the cable
2) Did you get the 12v when the camera was on load or disconnected.
3) same as one buy check all connections, check the psu, check the DVR log for times for when the signal was lost and see if it corresponds to anything else going on line heavy machinery running etc

Depending on what kind of tools you have see if you can measure the output of the camera, you should be getting 1vpp.

that was with camera disconnected.
would replacing the bnc connectors be an idea?
cameras seem to have there own mcb and its only general services fed from that board
could the fact that the rg59 may be running along side power cables?
not sure of its exact route

mazthespark

thanks for all the replies got all cameras working again had a variety of different faults some just unexplainable have one new camera that i just installed new cabling for the camera and cabling works prefect but when connected to the dvr it wont display on the system. have tried changing settings etc on camera but no luck. any suggestions?