Why my phone is hardly to charge?

@aisarrafiqi if it still has the original battery, I suggest you change that one first. Now, while you have the phone disassembled, consider replacing the charging board as well. It is possible that you are having issues with either the battery or with the charging board. Anything past that will be on the mainboard. To repair that, you would need to have the schematics, the knowledge and the tools to complete a full diagnostics and a boardlevel repair. Start with the easier things. Those are also not very expensive and can be done by pretty much anybody that has the patience and basic hand tools.

Since iFixit does not yet have the specific guides for those two things, use the guides from here Those are written in Spanish, use a browser that does the translating for you, if needed.

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!