you may first clean the speaker terminal contact pads on the PCB board if there is a corrosion and oxidation build up., then check the speaker using a multimeter to easily determine if it’s working or not. Replace a damaged speaker if found. If the speaker confirmed okay, you may refer to the solution below and do have a check and test procedure on some components which is associated or connected with the hands-free speaker
Huawei Y6 Pro solution for not working ringer, buzzer or hands-free speaker problem. This solution may help on how to troubleshoot and repair the phone handset.
How To Huawei Y6 Pro Speaker Ringer Jumper Solution Problem
Reviewed by Android Zone