Quick answer
One camera showing a black or blank image while the others are fine is nearly always a fault with that camera, its cable or its power supply, so check that single camera before you suspect the recorder.
A little methodical checking usually pins the cause down, and several of the common causes are things you can put right yourself in a few minutes.
What the picture is telling you
- Completely black, with no on-screen text. The recorder is receiving nothing at all from that camera, which points to power or cable.
- Black with a “no signal”, “video loss” or camera name on screen. The recorder knows the camera should be there and cannot reach it.
- Black at night only. The image is fine in daylight, so the camera works. The infra-red night vision is the problem.
- White, milky or washed out rather than black. Usually infra-red light bouncing back off a wall, a soffit, a spider web or a dirty lens.
- Every camera black at once. That is a recorder, monitor or power supply issue rather than a camera issue.
Common causes
At night, a black or unusable image often means the camera’s infra-red illumination is being defeated. Spider webs across the lens are the single most common cause, because the webs sit close to the illuminators and reflect the light straight back. Rain or condensation on the lens, a nearby security light, or a bright reflective surface in front of the camera can all do the same.
During the day, a blank image points more often at the connection. A cable that has been pulled, chafed, nibbled by rodents or damaged during other building work will break the picture. Water can also track down a cable into a connector, and outdoor joints that were never properly sealed corrode over time. Power is the other frequent cause: a failed power supply, a tripped fuse or a plug switched off during another job will take a camera offline while its neighbours carry on.
Cameras do also fail. Image sensors degrade after years of pointing at bright sky, and a camera that has taken a knock or a lightning surge may be beyond repair.
Checks you can make safely
- Look at the recorder screen and note the exact wording shown on the black channel. It is the most useful single piece of information when you call us.
- Check whether the problem is constant or only after dark, by looking at the same camera at both times of day.
- Clean the lens and housing gently with a soft, dry cloth, and clear away any webs. Only do this where you can reach safely from the ground.
- Check that the power supply for the cameras is switched on and that no socket or fused spur has been turned off.
- Look along any cable you can see for obvious damage, and check that outdoor connectors are dry and seated.
- Restart the recorder at the mains and allow two minutes. That clears the occasional software glitch.
Never work at height without the right equipment, and do not open a mains powered unit. If the camera is on a roof, a gable or above a first floor, leave it to an engineer with the right access equipment.
When to call an engineer
Call us if the camera is still black after cleaning and a restart, if more than one camera has gone at the same time, if you can see damaged cable, or if the camera is out of safe reach. Our engineers can often look at the system remotely first, confirm whether the recorder is seeing the camera at all, and arrive with the right part rather than making two visits. Call Advanced Overwatch on 028 7087 8077 and we will get your cover back to full strength.
Related reading
- Service page: CCTV installation in Northern Ireland
- Related guide: How do I view my CCTV cameras remotely?
- Related guide: How to Set Up Remote Viewing on Your Dahua CCTV System
- All of our guides: Knowledge Base