Google Nexus 5 :: No Speaker Or Microphone

My old Nexus 5 (vanilla 5.1.1 not rooted) is malfunctioning.There is no sound coming from the speaker in the bottom of the phone and the microphone is not picking up any sound when making a normal call and/or recording a video.The speaker at the top of the phone however, is working. So I hear people in phone calls, but they do not hear me.Now to the strange part: If I change to the loud speaker while in a call it's the opposite; I can not hear them but they can hear me.If I connect headphones into the headphone jack I can hear sound both in calls and in video playback.

So to summarize:
Playing video or music (YouTube, video recording, dialer sounds): No sound
Playing video or music (YouTube, video recording, dialer sounds) with headphones: Sound working
Recording video: No sound recorded
Making a phone call: Sound but no microphone
Making a phone call with loudspeaker on: No sound but microphone working
Making a phone call with handsfree connected: Not tested (I have no headphones with mic).

And what's even more strange is that I just replaced the flex cable with the microphone and charging dock and also the entire speaker with new parts from eBay. And guess what... it's still not working!!!