Open the microphone battery box, take out the battery, the measured voltage of 0.5 V (almost no electricity), remove the external MIC plug before recording. Troubleshooting. Many users with external MIC, forget to replace the battery in time, in the same period, cannot be taken voice, cause needless loss. There is a small doohickey actually, is to use the microphone volume level meter to monitor the volume level.nfBservice manual download site