I cannot hear the person Im calling?

I have replaced my rear panel and front assembly, everything is perfect but when I make a call I cannot hear the other person. If I press speaker then I can hear.

I took apart iPhone and made sure connector 1, 2 and 3 were seated correctly as this are the only thing I can think of.

Done this 3 times with no success....

Ok, it is connector 3 thats the problem, I have inserted it in several times but no joy. Is it possible that the from assembly I got on ebay is faulty or is the connector on my logic board faulty.

So Ive figured out the digitiser has nothing to do with it as connector 3 is not even part of it. Its the middle frame assembly that has connector 3. So can someone please tell me how to remove the earpiece and connector 3 on the frame.

That sounds fine but now Im thinking it could be the connector 3, the fps connector. How can I tell if it needs replaced as this is the connector for the earpiece and proximity sensor and this is also not working.