After speaker replacement the device still has no sound

this has not happened specifically to me, but i work at a cell phone repair shop, and have fixed this issue on other devices a few times.

1) Verify speaker function: though the part is new, it could be defective. plug the speaker into a 4V power supply, and it should let out a hum, with a small popping noise. thismeans its functioning.

2) Factory reset: if the speaker works fine, the factory reset will remove most generic software corruptions that could cause the issue. (This will erase all of your data). be sure to check settings and ensure the sound is enabled before trying this.

3) Verify current is being supplied to the speaker: i have an adapter i made that connects to the clip connectors, and i solder leads onto the pressure traces. connect the ends to a multimeter, and verify voltage while trying to make a sound on the device.

3b) if you find that you are not getting the required voltage, then you may have a board level failure, in which you need to diagnose. board level issues are not a home level repair, and i would suggest hiring someone with a background in the field.