Does P1 module produce any audible sound once its connected to a 3v power supply? I have 8 board build with P1 module on it. 7 out of the 8 boards have audible sounds. It have a distorting sound and sometime it click like something is turn on and off when I put my ear next to the board. Other then the sound, everything seem to be working fine.
The input voltage is 24 VAC, converter to 5v and 3.3v supply. When I disconnect the P1 module from the circuit no sound was heard. I also tried putting a load on the 3v power supply with out the P1 module and no sound was heard. Once I connect the P1 module the sound came back.
Could the P1 module not solder on right even everything else works except the sound?