broken Ear Phone Jack

If you can hear good sound from the internal speaker , you can change that part:

Remove and reinsert another spare headphone set.

If not fix,

You must open the device. Use ifixit disassembly to access the part that is in the picture.

Remove and reinsert the flex cable as seen in the picture. and test it again.

If it not work buy an original / genuine replacement part and throw it in. You have good chances to work.

If also this not work , here it have Logic board Issue. Go with wireless Bluetooth headphones, which i hate.

Hello Sari,

The headphone jack on an iPhone 6s is part of the charger port assembly. Changing this flexible printed circuit board accomplishes changing the jack as well as the cable that leads to the jack.

Bottom Flex

You should also be replacing the adhesive seal each time you disassemble and reassemble an iPhone 6s. It helps with water resistance.

iPhone 6s Display Assembly Adhesive

If your phone's continue not to function after replacing the flex, you will need to bring your phone I to a local repair center to diagnose the issue.