1,Problem Without output
Solution:Confirming the signal cable works and well connected or not;To make sure PHA1 turns on;Finally If set up a hearable volume.

2,Noise judgement
Solution:If you find there is noise when playing music,sometime it is problem from MUSIC original or Amplifier.How to judge it? Please pause your output,if there is no noise without output music,the noise is from Music file.

3,Not able to work by Micro USB powering
Solution:If amplifier work fine by 5V power adaptor,  but do not work by micro USB powering.

Please Check the status of USB cable and 5V usb power output.
 
If the listed solution can not solve your problem.Kindly email or call us or online chat!