phone turns off and never turns back on

@aikoyuuuii sounds like a power issue. You want to check your charger and your charging cable. Make sure that those do not have any broken, corroded or bend pins. Make sure that your charger has the proper voltage output. If all of that checks out okay, I suggest that you change your charging board as wella s your battery. Use something like this video to work on it. You do not need to solder a new port. Replace the complete board with something like this While you have your phone open, check for any damaged component/torn ribbon cable etc. If you need to clarify things, post some pictures of that with our Question. That way we can see what you see. Adding images to an existing question

If you need to do a board level repair, use something like the test points to see if you have power

Now use the search function of your PDF reader to find the test point on the board in this document Honor 8X (HL1JSNM) PCB Layout Do this only after you have changed your charging board and your battery. Do not get ahead of yourself.

After that, re-evaluate your phone and see if it now comes on. If not you may need to dig deeper into the board level of your main board.we will have to gig deeper into

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 the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.