Hello everyone. Forgive me my English but I have to ask for help.
I bought 6 x RPI Zero W and 6 x JustBoom Amp Zero pHAT for the Raspberry Pi Zero.
I am using volumio player, image file from volumio.org, a new micro sd card.
After a few days I observe strange behaviour. After changing volume from Android phone or PC sometimes I have silence in my speakers.
Sometimes I don’t touch volume control but the problem still occurs. Just like that. In logs I have a lot of messages:: pcm512x 1-004d: No SCLK, using BCLK: -2
Today I read about volumio api and after command /api/v1/commands/?cmd=stop I have STOP and success but after next command /api/v1/commands/?cmd=play I have PLAY and success but I can’t hear the music. Only information in log file: pcm512x 1-004d: No SCLK, using BCLK: -2
It is terrible. So much money and bug in hardware ? Meybe in software. I am confused. What can I do ? It is a global problem, I tested It with RPI zero, RPI zero W and always the same problem 
Help me…I spent a lot of money and time, I lost enthusiasm for this project.
Regards,
Mariusz