Posts in category: CCTV

You open the DVR and one or more cameras show a black screen with the message No Video Signal or Video Loss. It is stressful because it means that area is not being recorded. The good news is that the cause is usually simple: power, a cable, or a connector. This guide shows how to find the faulty part quickly instead of replacing things blindly.

What No Video Signal actually means

The DVR is telling you that it is not receiving a picture from that channel. The fault can be in the camera, the power supply, the cable and connectors, or the DVR itself. The fastest way to find it is to isolate each part one at a time.

Step 1: Check whether one camera or all cameras are affected

• One camera: the problem is almost always that camera, its cable or its connectors.
• Several cameras on the same power supply: suspect the power adapter or power distribution box.
• All cameras: suspect the DVR input, the main power supply or a recent setting change.

Step 2: Check camera power

Most analog and HD-over-coax cameras need 12V DC. Many cameras show a small IR light glowing in the dark when powered. In daylight you may need a multimeter.

1. Measure the voltage at the camera end of the power connector. It should be close to 12V.
2. If it is much lower (for example under 10V), you have a voltage drop from a long cable, an overloaded adapter or a weak power supply.
3. Check the adapter’s amperage rating. Add up the current of all cameras on it and keep a safety margin. A power supply running at its limit causes random video loss.

Step 3: Check the BNC connectors and cable

Bad connectors are the number one cause of video loss on coax systems.

1. Look for loose, rusty or corroded BNC connectors, especially outdoors.
2. Re-crimp or replace the BNC connector at both ends if in doubt.
3. Check the cable along its path for cuts, water damage or rodent damage.
4. Make sure power and video connectors are not touching each other.

If you use a balun on UTP cable, check that the balun is tight and the pairs are connected correctly.

Step 4: Test the camera with a known good setup

1. Take the camera to the DVR and connect it with a short cable and its own power adapter.
2. If it shows video, the camera is fine and the fault is in the long cable, connector or power at the original location.
3. If it still shows no video, try the camera on another DVR channel, or try a different camera on the same channel.

This swap test tells you immediately whether the camera, the cable or the DVR channel is bad.

Step 5: Check the DVR channel and signal type

Some DVRs support several signal types (for example AHD, TVI, CVI and analog) and some support both analog and IP cameras.

1. In the DVR menu, check the camera or channel settings and make sure the channel is enabled.
2. If your DVR has a signal type or HD format setting, set it to Auto or match the camera’s format.
3. If the DVR supports IP cameras on some channels, check that the channel is not set to IP mode when you connected an analog camera.
4. Check the resolution. Plugging a high-resolution camera into a DVR that does not support that resolution can give no picture.

Step 6: Look at the DVR itself

• Reboot the DVR properly from the menu.
• Check that the DVR is not overheating and that its fan is working.
• Update the firmware if your model has a known issue.
• If every channel fails after a power surge, the DVR input may be damaged and need repair.

Quick troubleshooting table

How to prevent video loss

1. Use good quality BNC connectors and crimp them properly.
2. Seal outdoor connections against water.
3. Use a regulated power supply with enough spare capacity.
4. Keep a spare camera, adapter and cable for quick swap testing.
5. Do a monthly camera check and note any camera that flickers.

FAQ

One camera is black but the others work. What should I check first? Check the power at that camera, then the connectors, then do the swap test with a short cable.

The camera works on a monitor but not on the DVR. Why? The signal type or resolution may not match the DVR channel, or the channel is disabled or set to the wrong mode.

Can a long cable cause No Video Signal? Yes. Long runs lower the power voltage and weaken the video signal. Use thicker power cable, a better video cable or a local power supply.

Do I need to replace the DVR? Only after you have confirmed that cameras, cables and power are fine. Most cases are caused by connectors or power.

Related reading: How to Set Up Hikvision DVR Remote View on Your Mobile | CCTV Camera Placement Guide for Factory and Warehouse | Network Printer Shows Offline: 7 Fixes That Work

Watching your CCTV cameras from your phone is one of the first things people ask for after a DVR is installed. With a Hikvision DVR it takes about ten minutes if the DVR is connected to the internet and set up correctly. This guide shows the easiest method (Hik-Connect cloud), explains the port forwarding method, and covers the security steps you should not skip.

What you need before you start

• A Hikvision DVR or NVR that is activated with a strong admin password.
• A working internet connection and a LAN cable from the DVR to the router.
• The Hik-Connect app on your Android or iPhone, and a Hik-Connect account.
• A few minutes in front of the DVR with a mouse and monitor.

Menu names change slightly between firmware versions, so use the steps below as a guide and look for the closest option on your DVR.

Step 1: Make sure the DVR has internet access

1. On the DVR, open Configuration, Network, General.
2. Check that the IP address, subnet mask and gateway are correct. The gateway should be your router’s IP.
3. Set the Preferred DNS to your router’s IP or to a public DNS such as 8.8.8.8.
4. Click Test or ping an outside address from the DVR if your model has that option.

If the DVR uses DHCP, consider giving it a fixed address so it does not change later.

Method 1: Hik-Connect cloud (easiest and safest for most offices)

This method needs no port forwarding because the DVR connects out to the Hik-Connect service by itself.

1. On the DVR go to Configuration, Network, Advanced Settings, Platform Access (on some models it is called Hik-Connect).
2. Tick Enable. Read and accept the terms if asked.
3. Create a verification code (also called encryption key). Use at least 8 characters and keep it private.
4. Wait until the status shows Online.
5. On your phone, open Hik-Connect, sign in and tap the + icon.
6. Scan the QR code shown on the DVR or enter the device serial number.
7. Enter the verification code, give the device a name and finish.

Your cameras will now appear in Live View in the app. You can also play back recordings if the DVR has a hard disk installed.

Method 2: Port forwarding (direct access)

Some people prefer direct access with the iVMS-4500 app or a PC client. This needs port forwarding on the router and is less secure if done carelessly.

1. Give the DVR a fixed IP address.
2. In the router, forward the DVR’s server port (default 8000) and, if you need video streaming, the RTSP port (default 554) to the DVR’s IP.
3. Find your public IP address or use a DDNS service, because many internet connections have a changing public IP.
4. In the mobile app, add the device by IP or domain, enter the port, username and password.

Security tip: do not expose the DVR’s web port 80 to the internet. Change default ports if possible, use a long unique password, and keep the firmware updated. If you need secure access from outside, a VPN to the office is a better option than open ports.

Common mistakes and how to fix them

• Status shows Offline: check DNS and gateway on the DVR, and check that the router has working internet.
• Cannot add device in the app: the verification code is wrong, or the device is already added to another account.
• Live view works at the office but not outside: with port forwarding, the ports are not forwarded correctly or the ISP blocks them.
• Video is slow or choppy: use the sub-stream for mobile viewing and check your upload speed. Remote video uses the office upload bandwidth.
• Time is wrong on recordings: set the DVR time zone and enable NTP time sync.

Security checklist

1. Change the default or old password and use a unique one.
2. Update the DVR firmware.
3. Create a separate user with view-only rights for people who only need to watch.
4. Disable services you do not use (for example UPnP if you do not need it).
5. Never share your verification code in public messages.

FAQ

Which is better, Hik-Connect or port forwarding? For most offices Hik-Connect is easier and safer because no ports are opened. Port forwarding gives direct access but needs careful security settings.

Is remote viewing safe? It is safe when you use a strong password, updated firmware and the cloud method or a VPN. Open ports with default passwords are the real danger.

Can I view the cameras on a PC as well? Yes. Use the Hik-Connect web portal or the iVMS-4200 software on a computer.

Does remote viewing use a lot of internet? Yes, mainly upload bandwidth at the office. Using the sub-stream and fewer cameras at once reduces the load.

Related reading: DVR No Video Signal Error: Causes and Fixes | CCTV Camera Placement Guide for Factory and Warehouse | Fix Wi-Fi Dead Zones in Your Office