Acer HARLEY TAB A3-A20 Service Manual page 62

7. No echo, fail to record
No echo, fail to record (but there has ring tone)
Check if MIC is soldered
Check if MIC sound
57
YES
well
NO
hole is jammed
NO
Yes
Replace MIC
NO
Replace MB
OK
YES
Re-solder or replace MIC
YES
Clean MIC sound hole
Replace MIC and make bad
YES
marks on the bad MIC
YES
Repair the MB referring to the
troubleshooting guide for L3 repair