Come risolvere:telecamera di sicurezza CCTV senza immagine

Se la tua telecamera di sicurezza CCTV mostra nessuna immagine , leggi questo articolo per ottenere alcuni suggerimenti e suggerimenti. Ecco una guida per la risoluzione dei problemi CCTV senza problemi di immagine. La guida viene utilizzata per le telecamere di sicurezza cablate che utilizzano connettori BNC e cavo coassiale. Si applica alle telecamere TVCC analogiche e alle telecamere di sicurezza coassiali HD (HD-TVI, HD-CVI, AHD). Nota:i suggerimenti mostrati qui non si applicano alle telecamere IP.

Nessuna risoluzione dei problemi relativi alle immagini video

Di seguito sono riportate alcune domande iniziali a cui dovresti rispondere durante la risoluzione dei problemi di una telecamera di sicurezza priva di immagini video.

Testa il tuo alimentatore

Prima di affrontare i problemi e le spese per l'acquisto di un monitor di prova o di un cavo CCTV di riserva, ti consigliamo di controllare per assicurarti di non avere un problema di alimentazione . L'assenza di immagini è principalmente causata da un problema di alimentazione, la fotocamera non si accende nemmeno.

Molti sistemi TVCC includono trasformatori di alimentazione CC individuali per ciascuna telecamera (come quello nell'immagine sottostante). Se non ne hai uno di riserva, puoi trovare gli alimentatori per telecamere di sicurezza qui.
Assicurati di controllare l'alimentatore esistente per confermare se è 12VDC o 24VAC . La maggior parte sono a 12 V CC. Scollega l'alimentatore esistente dal cavo e collega quello di riserva. Collegalo e prova a vedere se la tua videocamera ora visualizza video.

Controllare i fusibili della scatola di alimentazione

Se il tuo sistema di telecamere di sicurezza utilizza una scatola di alimentazione TVCC , ti consigliamo di controllare i fusibili all'interno della scatola. L'immagine sotto mostra l'interno di due scatole di alimentazione CCTV.

Quello a sinistra usa i tradizionali fusibili monouso. Quello a destra utilizza i "fusibili a ripristino automatico" PTC. Entrambi i tipi hanno un interruttore di accensione/spegnimento che consente di controllare l'alimentazione dell'intera unità.
Segui questi passaggi per risolvere i problemi del tuo alimentatore.

1. Assicurati che l'interruttore di alimentazione sia acceso e che le spie LED di stato siano accese.
2. Se la tua scatola di alimentazione utilizza fusibili tradizionali, verifica che nessuno dei fusibili sia bruciato. Se uno è bruciato, la luce del LED sotto quel particolare fusibile sarà spenta. Dovresti sostituire il fusibile.
3. If your power supply box uses PTCs, instead of fuses, confirm that the LED lights are on for all channels. If they are not, you may have a short circuit somewhere. Disconnect each camera one at a time to see which one is causing the problem.
4. Confirm that the wire power connections are securely in place and have not become loose or disconnected.

Test the camera on a different DVR port

This is uncommon, but it is possible that one of the BNC video input ports on your DVR went bad. It is a simple thing to test, so you may as well give it a try before you spend time on the other troubleshooting steps. Since you’re already at this step, make sure the connection is not loose, on both sides:the camera side and the DVR side .
Disconnect the BNC video connector of the troubled surveillance camera from the back of your digital video recorder and plug it into one of the ports where a working camera is plugged in. Plug the BNC connector of the camera that is working into the port of the camera that is not working.

Does the working camera show video on the other BNC port? Does the troubled camera display video on the other port? If the troubled camera works and the camera that was working does not work, then you have a bad input port on your DVR.

Use a test cable and spare power supply

We recommend that you use a spare cable for testing. These pre-made Siamese CCTV camera cables are a great choice. They allow you to run both the video and power.

Using a test cable will be feasible only if your existing cable run is not longer than 165 feet – the max length that pre-made CCTV cables are made.
Here are the troubleshooting steps that we recommend if you are going to use a spare cable.

1. Before you go through the trouble of unwinding and running a spare cable from your camera to your DVR, we recommend that you check your existing power supply.
2. Confirm that your spare cable is long enough to reach from your camera to the DVR or monitor that it is connected to.
3. Disconnect only the BNC video cable from your camera and attach the spare cable.
4. Disconnect the other end of the video cable from your DVR or monitor and attach the spare cable. Test to see if there is video.
5. If there is still no video, use the power portion of the spare cable to run the power.
6. If still no video, switch out the power supply.
7. If there is still no video, you most likely have a bad camera.

Use a test monitor

If you have confirmed that your power supply is working properly and that the ports on your DVR are also working properly, the next step would be to determine if you have a bad power or video cable. Using a test monitor is one way to do this.
A CCTV test monitor is extremely helpful when troubleshooting camera video issues. One of the most common problems, when a camera is not displaying video, is a bad cable or BNC connection. Using a test monitor, you can temporarily eliminate the power and video cable that your camera is using.

Many CCTV testers, like the one above, have a 12V DC power output that can be used to supply power to your camera.

Here are the steps that I recommend if you are going to use a test monitor to troubleshoot.

1. Disconnect the video cable from your camera and use a short RG59 BNC jumper cable to connect the video output of the camera to the BNC input of the test monitor. If your camera is already mounted and connected to a power supply, I recommend that you first only connect the camera’s video to the input of the test monitor.
2. If you do not get a video signal, disconnect the power cable from your camera. If you have a test monitor that can supply power to your camera, connect the power output of the monitor to your camera.
3. If you do not get any video signal after switching the video cable, power cable, and power supply, you most likely have a bad camera. If you have a spare camera, connect it to the test monitor to make sure that it is working properly, then connect it to the existing cable and power supply of the camera you are replacing.

Note: if you are replacing your camera, make sure the replacement camera uses the same type of power supply before connecting it. If your previous camera used 24VAC and you connect a 12V DC camera to a 24VAC power source, it will burn the circuit board and ruin the camera.

Security camera DVR compatibility

If you recently purchased a new DVR or a new security camera, you should confirm that the video format(s) that they support are compatible. We find that many people have purchased a 720p or 1080p replacement camera for their 960H DVR.

This will not work. If you have an analog 960H DVR, you can only use a CCTV camera that supports analog 960H video.
Many of the latest DVRs and cameras are “hybrid” which means they support multiple surveillance video formats. The above image shows a 4-in-1 analog CCTV / HD dome camera . Notice the small joystick that is attached to the video cable.

The video output of the camera can be switched by holding the joystick up / down / left-right for 5 seconds. This particular camera supports AHD, HD-TVI, HD-CVI, and analog 960H (CVBS) video formats.

If you are using a 960H type DVR that only supports analog video (CVBS), you must use a hybrid camera in analog CVBS mode for it to work with your DVR. You will most likely need to consult the owner’s manual of your DVR to know what video format(s) it supports.

Replacement CCTV camera recommendation

If you need to buy a replacement CCTV camera, we highly recommend these 4-in-1 security cameras – especially if you are using an analog 960H or D1 format CCTV DVR. These hybrid cameras support analog CCTV format and multiple HD video surveillance formats (such as HD-TVI, HD-CVI, AHD).

They can be used in analog CCTV mode with your existing DVR and later switched to one of the HD video modes if you upgrade to an HD surveillance DVR.