JDM-055 PS4 Controller problem - charging light without cable


I have a problem with my PS4 JDM-055 Controller. I bought it with some tooth marks of a dog (no real bites, scratches) and the previous owner mentioned an usb plug problem.

I took a new case and tried it, everything works fine but there ist always the charging light flashing. connected to the PS4 it shows charging in the menu.
If I connect the USB, the charging light turns from yellow to orange. (and it charges actually)

I can unplug the USB Board, then there is also the charging sign in the menu, of course no LED anymore as it is unplugged too.

I looked in shematics I found, no good news, maybe a problem in the PMIC?
What makes the controller think it is charging?

The problem is, the LED flashes until the battery is empty and always unplugging it would be very uncomfortable…