Why does my Tegui video door phone not display an image?
One of the most common problems reported by Tegui video door phone installers and users is image loss on the monitor. The screen appears black, flickering, or simply does not show the signal from the outdoor panel's camera. In this guide, we explain the most common causes and how to fix them step by step.
1. Check the system power supply
Before checking the wiring or devices, verify that the video door phone's power source is working properly. Insufficient or unstable voltage is one of the most common causes of image loss.
- Make sure the Tegui power supply provides the correct voltage (check your model's manual).
- Measure the voltage at the monitor and panel terminals with a multimeter.
- If the voltage is below the specified level, replace the power supply.
2. Check the wiring between the panel and monitor
The video cable is the most sensitive part of the system. A bad connection, damaged cable, or excessive length can cause image loss.
- Verify that the cables are properly connected to the terminals on the outdoor panel and the monitor.
- Check that there are no damaged splices or pinched cables.
- For Tegui 2-wire systems, make sure the pair used has the appropriate gauge (minimum 0.5 mm²).
- For long installations (over 100 m), a signal amplifier may be necessary.
3. Check the jumper configuration
Tegui monitors and panels have configuration jumpers that directly affect the video signal. Incorrect settings can cause the monitor to not display an image.
- Check your model's manual to identify the video termination jumpers.
- In systems with multiple monitors, only the last one on the line should have the termination jumper activated.
- Also check the jumpers on the outdoor panel.
👉 Related article: Guide to configuring the N, P, and M jumpers on Tegui and BTicino monitors
4. Problem with the outdoor panel: defective camera
If the wiring and power supply are correct, the problem may be with the integrated camera on the outdoor panel.
- Temporarily connect another monitor to the system to rule out the monitor as the problem.
- If there is no image with another monitor either, the fault is in the outdoor panel.
- Check if the panel has any visible physical damage (impacts, moisture, oxidation on contacts).
- In that case, the outdoor panel needs to be replaced.
5. Defective or faulty monitor
If the panel works correctly with another monitor, the problem is with the original monitor.
- Perform a factory reset of the monitor (consult your model's manual).
- Check that the monitor firmware is updated (on WiFi models like the Tegui Classe 100X16E).
- If the monitor still does not display an image after the reset, replacement may be necessary.
👉 Related article: Tegui Classe 100X16E WiFi Monitor (Ref. 344786): compatibility guide before buying
6. Electromagnetic interference
In industrial installations or with a lot of nearby electrical wiring, interference can degrade the video signal.
- Separate the video door phone wiring from the power wiring (minimum 30 cm separation).
- Use shielded cable if the installation requires it.
- Avoid running the cable near motors, frequency drives, or fluorescent lights.
7. Specific problems in WiFi systems
If your Tegui monitor is WiFi (like the Classe 100X16E), image loss may be due to network connectivity issues.
- Verify that the monitor is properly connected to the WiFi network.
- Check the WiFi signal strength at the monitor's installation point.
- Restart the router and the monitor.
- Make sure the Tegui app is updated.
👉 Related article: How to connect the Tegui Classe 100X16E WiFi monitor to the app step by step
Summary: quick diagnostic steps
- Check the power supply (correct voltage at terminals).
- Check the wiring (connections, gauge, length).
- Verify the jumper settings.
- Try another monitor to isolate the fault.
- Check the outdoor panel (camera, contacts).
- Rule out electromagnetic interference.
- In WiFi systems, check the network connectivity.
Do you need spare parts or a new Tegui monitor?
If after following these steps the problem persists and you need to replace a component, in our store you will find original Tegui monitors, panels, and accessories with fast shipping throughout Spain.
