Ear Speaker replaced, still not working.

First off, my GF's iphone 4s power button was broken, so i replaced the whole assembly (power button/speaker/proximity sensor/flex cable) and right after that the ear speaker didnt work. It was working before, with the broken power button.

Now the power button works and the ear speaker doesnt. So i have replaced the ear speaker with a new ear speaker assembly, which didnt work.

I thought maybe i was cheap and bought a faulty one, so i bought another and still doesnt work.

Ive had checked and doubled checked that the ear speaker prongs lined with the logic board, prongs pointing north of the phone, but all i've gained through this is small static sounds.

I have cleaned the speaker holes, tried sucking on it, tried blowing on it, tried resetting phone, tried pushing, knocking, everything that was suggested on this forum.

I guess what i wanna ask is, whats the chances of it being the logic board that is the problem?

The underside of the logic board has 2 contact strips, it has 1 very small marks on each of them from the friction and contact of the points from the ear speaker. But i think thats normal?

Everything else on the phone works.

I would be really appreciated if anyone can shine some light on this for me.

Thanks