Why headset no connection

@umar90027 your headphone jack is mounted to the daughter board. Replacing that should resolve the issue. You do want to check that the flex cable from the daughter board to the main circuit board is in good working condition. That means properly connected, no tears and no corrosion.

Of course, make sure everything within your phones settings are properly set etc. Since iFixit does not yet have a specific guide for the daughter board replacement, use something like this video The board is readily available at many online stores.