No sound on headphone jack and Lightning but on speaker

Hello,

I hope someone may help me as I do not know any more what I made wrong.

I changed the logic board of my old black 5S with broken display (64GB) into the white one of my daughter (16GB). Everything runs well only there is no sound on the headphone jack and on the lightning connector but on the speaker.

When I listen very carefully I can hear something but only on highest sound level and when it is very calm around me.

I still checked the connection of the connector close by to the battery connector and I tried also the headphone jack/connector part from my old 5S and this shows the same problem.

Any idea what could be the cause. Is there a risk that I damaged the logic board?

Thanks in anticipations

Michael