ESU DCC Sound decoders with specific sounds are programmed by TecnoModel on the spot and carefully tested to ensure correct operation before shipping.
Therefore, if once installed it doesn't work / doesn't make any sound etc. it means that there was a problem during installation or programming, and it was damaged.
It is probably sufficient to carry out the reset (CV 8 = 8) to bring it back to the factory values.
Generally, the decoder is damaged because the speaker terminals accidentally come into contact with the line coming from the track or with a solder on the PCB of the model. In this case it is necessary to send it to the manufacturer for assistance.
Write to info@tecnomodel-treni.it specifying the order number, the item code and the problem encountered, and we will provide you with the instructions to send the decoder for assistance.