@piousmavuso9647 you are not telling us what the issues with your "charging System" are. For now, I would suggest you replace the charging board (sub_board). Since iFixit does not yet have a guide for that, use something like [https://www.youtube.com/watch?v=imeZe1b3Ju0|this video] to work on it.
While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has a device with the same issues as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.
Repair is War on Entropy!