no video . does not turn off when I press the power button.
voltage of 3.3v and 5V normal.
normal memory supply voltage
I do not realize heating in bga north and bga south
I did not find schematic diagram of the motherboard
sem sinal ou tensão nos pinos (D +) e (D-) no conector usb
I suspect that the South Bridge is not receiving power source

Are you getting the enable signals for the DC/DC converters? If so, what about other voltages? Make measurements at the inductors.