No sound through loud speaker and only one channel through headpones

I have an iPhone 5s with which plays no sound through the loud speaker and only one channel through the headphones. I already replaced the dock flex cable which consists of the headphone plug and the routings to the loud speaker. I already reset the iphone completely, also to no avail. Might the motherboard connections to the dock flex cable be damaged?

Can someone help me?

I managed to solve it by cleaning the motherboard connector really good (with alcohol and a soft tooth brush) and firmly pushing in the connector of the new dock flex cable.

Thank you anyway!