Earpiece, Headphone Jack, Buzzer does not work even after replacement.

Okay here is the problem with my iPhone 6. The earpiece (where you heard the voice of someone you called), headphone jack, and buzzer does not work.

When i plugged in the headphones, it did not detect it at all. Same goes when i call someone or someone called me, i cannot hear their voices, and when i speak, they cannot hear my voices.

I've already replaced all the parts mentioned above, which is the earpiece, the buzzer, the headphone jack, but it all comes to no avail.

What does work? My front camera works well, and I can even hear music through the speaker.