Have asus x553ma motherboard in dead condition 19v rail is ok but 3v 5v and all voltages fluctuate on power switch 3v is stable. Help with diagnose this problem
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Re: Asus x553ma no power
Hi. Remove all power. Measure the resistance to ground of each inductor / coil on the logic board.
If the voltage is fluctuating -> measure there resistance to ground to see if there is a short condition.
Next, locate the power regulator for the rails that are bouncing. What is the regulator's topside markings ? Very likely the regulator will have an ENABLE pin.
Power up and measure the voltage to ground of the ENABLE pin. Is the ENABLE pin also toggling ON/OFF ?
Often, a current sense loop will force the regulator to shut off. The current draw is known in advance by the designers and if the current draw is exceeded, the regulator will be shut off.
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