AudioMoth ceased recording sound

Hi the Team

When analyzing the .wav of one of my AudioMoths I found only 'scratching' sounds.

File names, timestamps and file lengths are correct, so just looking at the file list, everything seems normal.

I could track back the moment when it ceased to record sound on 3-may-2020 at 06:03:21. The file begins with recorded sounds, then the noise only for 3 seconds, sound again for half a second, then noise the rest of that file and all the subsequent files. Image attached.

I suspected batteries and SD card so I made different tests changing batteries and swapping SD cards. Same thing either in custom or default mode. So I came to the conclusion that the problem comes from the AudioMoth itself, possibly from the analog part ?

It's an AudioMoth from Round 5 (ID: 24CE97035AA4F124). It's twin brother still runs fine and well and they both have been used in a similar way for one and a half year. Firmware is 1.2.1. Sampling rate 192 kHz and Gain 2. That night was dry with no wind and temperatures in the 9-12 degrees C. As it was the Dawn Chorus Day, another audio recording was being conducted from the exact same place. There was no special sonic event at this time.

Are there some other tests I could do ? Or do we have to declare this AudioMoth dead ? Could it be sent for repair, or at least for analysis ?

Thanks.

Pierre