The speaker does not work at all in my mx4 after replacing the motherboard ' I replaced another speaker that does not...

After I broke the screen I purchased new and changed it by guides on YouTube and I changed the screen and everything worked but the sensor of the home button no longer worked more I tried all the guides and nothing worked until I changed and no reason the lcd metal backplate with home flex cable !!!!!!!!!! And wowwww the home button start working perfectly... Sooooo probably the first flex cable was damage and I didn't see this... In conclusion - try to replace everything related directly or indirectly to the screen or the home button but of course not the button itself. Once I plugged all previous fingerprint device's memory is kept and everything works perfectly, Hope That I've had help someone [email removed for privacy]