We assume the presence of a short circuit.
Using an automatic Fluke multimeter, we checked the main power circuits of the phone for the presence of working resistances in them.
We measured the following circuits:
The resistances in the above circuits corresponded to the resistances of the working device.
Since there is no short circuit in the main circuits, and the power controller is heated, it was decided to disassamble the main power controller for further diagnostics.
Since the CPU and Baseband are covered with compound and are located on the reverse side of the Board, opposite the CPU, there are risks to disrupt the soldering of the pins of these chips (overheating of the Board). In order to avoid overheating of the CPU or modem, it was decided to cut down the main power controller on the CNC milling machine.