If you had to transfer the charge port over, it can be a little tricky aligning the flex cable connector. Rebooting can be caused by a few things, a faulty or aftermarket charge port, or a damaged power or volume flex cable. If you can get it to connect to a computer, you can use this video to read the panic log to help pinpoint the cause of the problem: https://www.youtube.com/watch?v=QaJLYbtuCGA&t=225s