Step1:-check the hand free jack is it sold ok and if not you can resold it carefully so that not a single pin remain untouched.
Step2:-Wash the jack i mean clean it with any electronics cleaner like ctc and leave it for a few mints so that it can be dry.
Step3:-If it is not solved with the uper steps remove the little ic shown in the diagram.
Step3:-and make jumpers as shown in the diagram with red lines.two prints from the jack to resistance and own jumper with the removed ic points as shown in picture.
Step2:-Wash the jack i mean clean it with any electronics cleaner like ctc and leave it for a few mints so that it can be dry.
Step3:-If it is not solved with the uper steps remove the little ic shown in the diagram.
Step3:-and make jumpers as shown in the diagram with red lines.two prints from the jack to resistance and own jumper with the removed ic points as shown in picture.