Video Loss Troubleshooting for DVRsThis guide will aim to provide some common troubleshooting actions for when one or more of your cameras connected to a DVR are not showing an image. Some of the troubleshooting steps will seem quite simplistic and may be unnecessary. However, if you skip steps, then you may well miss something simple, yet important.
Please note, this guide does *NOT* pertain to NVRs, which have some more complex rules to follow.
Which video loss is it?There are 2 types of video loss - cameras and monitor. Monitor video loss is where the DVR is unable to be seen at all on the screen that is attached to the DVR. Camera video loss is where the cameras are unable to be seen on the recorder’s display (and by extension the attached screen). This guide does not address the monitor video loss as the troubleshooting for that issue is generally straightforward and requires only a single change on the recorder. We will only be looking at camera video loss in this guide.
Is it the cameras or the screen?To determine if the video loss is related to the cameras, the quite simple test is to attempt to bring up the recorder’s menu screen. If you right-click with the mouse, you should see a response on the screen where you see a menu of some type. If you do not see a menu (indeed, if you cannot see any camera divisions at all) then it is an issue with the screen and you will need to check your settings for output on the recorder. If you get a menu, then you can close that and proceed with troubleshooting in this guide.
Check power supplyObviously, without power, the cameras will fail to operate. Checking our power input should be the first step.
Check camera IRsTo try to determine if the cameras are receiving power, we will look for activation of the nightvision IR LEDs.
- Cup your hands around the front of the camera.
- Place your eye up to your hands, keeping out as much light as possible.
- Look for the slight red glow that indicates the IRs are powering up.
Check power supply in useIt goes without saying that the cameras will not create a usable signal if the power is not connected.
You should check first that your camera power supply (or supplies) are properly connected to a wall socket or power strip. If you do have the power supply connected to a power strip, try a wall socket just in case the power strip is faulty or is a specialised unit that doesn’t have all the sockets active at all times.
Then make sure that your power cable is connected to your power splitters for input into the camera cables.
Check power splitters (if applicable)Your power splitters go on the end of the power cable of the power supply. These then split the output from the power supply so that multiple cameras can share a single power supply. These then connect into the camera extension cable at the DVR end.
- Ensure that you can trace a power line all the way from the power supply, through a splitter and into each of your camera cables.
- Ensure that you have only used *ONE* splitter per power supply.
Check physical connectionsThe cameras must be connected to the signal inputs on the rear of the recorder. If these are not connected, or loose, then you may experience interrupted signal.
Check cables into recorder
- Check that each camera cable is connected to a camera channel input.
- Be aware that some recorders have similar connectors for ports that are not camera inputs.
- Check that the connectors are fully locked, and that the connectors themselves feel tight. There should be very little give when connected correctly and not able to be removed just by pulling.
Check cables into cameraAs above, the camera connections should be tight and fully locked, the signal connection will be unable to be removed just by pulling. All DVR cameras have separate power and signal connections and both need to be connected for the camera to operate.
Check signal typeUnfortunately, with the advent of HD over Coax DVR cameras, the days of cameras for DVRs being universally compatible are over. It may be that you have selected the wrong camera for your recorder, or there are additional settings you need to complete before you cameras will operate correctly.
Correct camera for the DVR?The camera you are using may be using a signal type that the DVR is unable to understand. This can be a bit tricky to determine if you have selected a camera that is incompatible, but you will usually find references in the documentation to analog, TVI & AHD. These are the 3 technologies that Swann uses, and you should cross-check your camera and DVR documentation to see which signal types each component uses. You can also check our Camera Compatibility Chart available on the Swann website.
Cameras that can change signal typeCertain new cameras will have the capability to change the type of signal they output to maintain compatibility with less advanced DVRs. These cameras will usually have a control on their attached cabling (usually a button or stick control) that you can use to adjust the signal output. Check your camera documentation to confirm the control method for signal output, and try all the options available to test if one of the signal types is compatible.
Advanced TroubleshootingIf you have tried all of the above and still are unable to resolve the issue, then it is possible that there is a faulty component that is causing the issue. The next troubleshooting guides are less about correcting the issue than they are identifying potential problem components for repair/replacement.
That’s not to say that you won’t find something that you can resolve yourself of course.
Isolation TestThe first test centres on making sure that there are the minimum required components connected to determine if there is a problem with one particular component. Some malfunctions can affect the other cameras which will result in a larger number of cameras malfunctioning, when only one camera or component is the cause of the malfunction.
Disconnect camerasYou should remove all camera cables from the rear of the recorder. Make sure that the connectors are completely separated and not touching anything metallic (including other cable connectors).
Disconnect power supplyNext, disconnect all the power connections from the camera cables. In particular, disconnect any splitters from the end of the power supply cables. We do this to have the minimum required components online for testing purposes.
Connect one camera onlyNext, you will reconnect one (and only one) camera cable to the rear of the recorder. Then, connect one power supply lead to the camera cable. Use the power supply cable and the same camera connection on the rear of the recorder to ensure a clean test.
Interpreting the resultsIf all the cameras fail to work on the same port, change power supplies and set the power supply that did not work as suspect. If they still fail to work after you have changed through all your power supplies, proceed to Port Test. If you find one or more cameras that do not work when they are connected this way, proceed to Cable Test.
Cable TestIf we have identified one or more cameras that fail on the Isolation test, the next step is to verify that the cable is working. Replacing a camera when the cable is at fault is both costly and time-consuming, when the issue could have been resolved by proper testing.
Setup as Isolation TestAs before, set up your camera according to the Isolation Test. This time we are only checking the cameras that failed the Isolation Test.
Cross check the camera and cableNext, you should disconnect the camera from this cable. Then, connect one of the cameras that did not fail the Isolation Test. We are testing the cable here so we need to use a camera that has worked before.
Interpreting the ResultsIf you connect up a different camera and the camera fails to show an image, then the cable is suspect. Mark it and move on.
If the previously working camera still functions when connected to the cable, then the original camera is suspect. Set it aside.