BTicino ART.344182 Receiver No Sound or Video with SCS 346830 Module and 343001 Doorbell

Hello, I have a BTicino system: a BTicino ART. 344182 receiver, a BTicino SCS 343001 doorbell, and a BTicino SCS doorbell module/call relay – model 346830, and a BTicino SCS 346000 power supply/controller (BUS 27 V). I ran 230 V to the power supply, a 2×1.5 mm² cable from the power supply to the module (PS), a 2×0.5 mm² cable from the module (TK BUS) to the doorbell, and a 2×0.5 mm² cable to the receiver (PI BUS). The doorbell has a 2×1.5 mm² cable to S- and S, and an electric strike to the gateway. The problem is that the signal to the gateway works, but there is no sound signal to the receiver or video. Could the 346830 doorbell module be faulty? I've checked the wires, and everything works. The addresses are correct. Thanks in advance.
AI: Does the receiver (ART.344182) power on normally—do you see any lights, display, or menu when you try to use it?
No, it just beeps when I try to press a button.
AI: Has this system ever worked before, or is this a new installation/setup?
Yes, this is an old installation; all connections checked.

Ref. 346830, is a video adapter, not a bell module.

Check the voltage at each BUS location, i.e. at each component.