This is, by far, the most frustrating CCTV problem. You can live with flickering or noise for a little while, but what if you can’t get a picture in the first place? This problem manifests itself in various ways:

Check that your camera is correctly powered. It may seem obvious, but we’ve all been bit by this. Even experienced security engineers will occasionally realize, with an embarrassed look on their faces, that a CCTV camera has no video signal because it’s not powered on.

• First, and most obvious: check the power connectors and the cables — make sure they’re plugged in and undamaged. If your CCTV camera has an external power brick, make sure it works. If you have access to that sort of equipment, try to power on your CCTV camera with a test cable and power supply.

• If your CCTV camera is connected to mains, or if it’s connected through a CCTV power supply with a fuse box, check the fuse box.

• If your camera uses PoE, check the PoE switch and make sure the camera is really being powered on.

Check your camera’s video or data connection. If you can’t get a picture on your CCTV camera but it is powering up, perhaps the images aren’t making their way to the monitor.

• If your camera connects to a DVR box, check the cable and the connectors at both ends. Make sure they’re correctly plugged in and undamaged. A CCTV test monitor can help in this case.

• If your camera is IP-enabled, make sure the network settings are correct. If it’s a wired camera, check the cable and the connectors for damage.

• Check any additional network or video equipment. If your CCTV camera connects to any network switches or routers, DVR boxes or video multiplexers, make sure they’re in working order.

Check your CCTV software. Advanced video surveillance software allows you to disable access to some cameras or to protect some streams with a password. If that’s the case, make sure that you can really view the stream you’re looking for.

Check your camera for damage. We’re at the end of the road here. If the camera is properly powered on and there are no connectivity problems, it’s time to check that there’s no problem with the camera itself. Make sure the lens and any protective domes are undamaged and the optical path is unobstructed. If the camera shows no external signs of damage, reaching out to the manufacturer for tech support is your next best option.