Volume botton not working

@agushardiyanto it could be the mechanical button but most likely it is a bad flex cable. The part you are looking for looks like this Just an example, not en endorsement.

Since iFixit does not yet have a specific guide for that, use something like 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!