Asus ZB551KL Training & Trouble Shouting Manual page 52

Main MIC Abnormal (1)
• MIC_BIAS1_Main without 1.8V
– Check L899, C826, U1001
Blow air flow to mic device,
MIC1_P_1/MIC1_M_1 no signal
- Check mic device and, L815, C825
• PMIC_AUDIO_REF_CLK no signal
– Check R410, U0501