Controller wont charge or power on

I'm trying to fix my friends Dualshock 4 but I can't seem to figure out the issue. I've never tried to fix a Dualschock controller so I could just be missing something.

The controller will not charge at all (light bar wont turn on either). I have replaced the battery and the USB charging port alongside with the ribbon that connects the port to the board. Nothing happened when I replaced the battery, but after replacing the USB port I noticed that the controller circuit board was getting hotter when I had the USB plugged in. Although, the controller still wont charge or turn on.

I was just wondering if anybody had any suggestions on what the issue and fix could be.

Thanks,