The 5+N coaxial Tegui system: why it remains in many buildings
The conventional 5+N coaxial Tegui video intercom was for decades the reference standard in Spanish residential installations. Its architecture combines a coaxial cable for the video signal with additional wires for audio, power, and signaling, which at the time offered image quality far superior to purely analog audio systems.
Today, although Tegui no longer markets these devices as new products, there is a huge installed base in residential communities, office buildings, and single-family homes. The installer facing one of these systems has two options: repair it if the fault is isolated and components are available, or replace it when the fault is structural or the repair cost is not justified.
Quick fault diagnosis
Before quoting anything, it is advisable to precisely identify the source of the fault. The following table lists the most common symptoms:
| Symptom | Probable cause | Recommended action |
|---|---|---|
| No image on the monitor | Defective coaxial distributor or damaged coaxial cable | Measure signal on each section; replace distributor |
| Image with noise or snow | Oxidized or poorly terminated coaxial connector | Redo connectors; check impedance (75 Ω) |
| No audio (video only) | Audio wire cut or voice unit faulty | Continuity in audio wire; check voice unit |
| Doorbell does not ring | Defective panel button or call wire cut | Bridge button to isolate; measure continuity |
| Monitor without power | Power supply faulty or fuse blown | Measure voltage at power supply terminals |
| Door opener does not operate | Door opener relay or control wire defective | Manually activate the relay; measure control voltage |
Repair: components still supplied
For 5+N coaxial Tegui installations, the most in-demand spare parts still available are:
-
Coaxial distributors: allow splitting the video signal to multiple monitors without degradation. Available in our store:
- TEGUI Coaxial 4-Output Distributor — 55,23 €
- TEGUI Coaxial Stair Distributor — 55,41 €
- Separate coaxial camera interface: solution to integrate a separate video camera into existing coaxial installations, maintaining compatibility with the 2-wire bus.
For the rest of the components (monitors, door panels, original power supplies), availability is very limited or nonexistent. In that case, partial or total system replacement is the most reliable route.
When is it no longer worth repairing?
There are situations where repair is not the smartest option, even if technically possible:
- The monitor or door panel is faulty and no replacement is available. Replacing only one of the two components requires compatibility with the rest of the system, which is rarely feasible with discontinued equipment.
- The coaxial wiring is damaged (crushed, damp, with poor splices). Reworking wiring in an existing building has a labor cost that usually exceeds that of a new 2-wire installation.
- The customer wants remote access or video calls on their mobile. The 5+N coaxial system does not have this capability natively. Adding it requires additional gateways whose cost approaches that of a new system.
- More than 30-40% of the monitors are faulty. Beyond that threshold, a complete replacement is usually more economical and provides the customer with warranty and support.
Replacement: migration options
When the decision is to replace, the installer has two main routes depending on the condition of the existing wiring:
Option A: Migrate to 2-wire system (using existing wiring)
If the installation wiring is in good condition, Tegui/BTicino 2-wire systems often allow reusing part of the existing wiring, reducing installation costs. This is the most common option in community building renovations.
Check our full collection of 2-Wire Video Intercom and 2-Wire Intercom to see compatible monitors, panels, and accessories.
Option B: Migrate to IP system
For buildings with structured network infrastructure or projects where the client demands native remote access, migrating to an IP system is the most complete solution. All signals — video, audio, and data — run over the existing LAN network, eliminating dedicated video intercom wiring.
Check our collection of Digital Video Intercom and the monitors from the Tegui and BTicino Video Intercom Monitors range.
Original technical documentation
If you need to consult the installation diagrams, original wiring, or electrical specifications of the Tegui 5+N coaxial system, the official technical manual is available for download:
📄 Download Tegui Conventional 5+N Coaxial Video Intercom Technical Manual (PDF)
Conclusion
The Tegui 5+N coaxial video intercom is a robust system that has provided excellent service for decades, but its lifecycle as an active product has ended. For the installer, the key is to make an accurate diagnosis: if the fault is in the coaxial distributor or the camera interface, the repair is viable and economical. If the problem is in the board, the monitor, or the wiring, replacing it with a modern 2-wire or IP system is the most cost-effective decision in the long term for the customer and the most professional for the installer.
At Tegui Distel we help you with available spare components and the full range of modern systems so you can budget the best solution in each case.