It seems that the device is repairable. The mic is supposed to be replaced though. Thanks again for your help.

Thank you Alex, I will! I hope it is repairable. Paolo

LabMaker. It worked perfectly when I received it. It must have happened something later. How can I understand if there are signs of water problems?

Hi Alex! Everything else seems to work perfectly. The device was kept in the house and in its case. No sign of corrosion or water. It is nearly brand new. I also think it is due to a damaged mic.