Chosen Solution
Hi guys, Thought I’d change my battery on my 5s (I KNOW - not many people would do that nowadays but I thought …. why not). All went well - except from sound isn’t coming out from the phone (so when i’m playing a YouTube video, or when someone rings me you get no sound) I also get no sound out of my earphones when I plug them in. I am however able to hear someone when they phone me and they can hear me. I’m just a little bit sceptical as to what part I need to look into again…. Thanks a lot!!
As @c9679 suggests, double check that the Lightning Port Flex (It contains the headphone jack and connections for the speaker) is properly plugged in and that the flex and/or connector is not damaged. Check out this guide for more details about this section of the phone.