With the adapter connected, check the voltage to ground of each coil (inductor) on the logic board.
You are checking for any low voltage measurements on the coil to ground. Each coil is linked to a local buck switching regulator. If the coil is with a low or zero voltage, that power rail could be defective or disabled due to a shorted part. A shorted part will consume too much current and the regulator will sense this fault and turn off the regulator.
Otherwise, you need to review the BIOS devices on the logic board which may be corrupt.
Comment