#1 ASUS X541U NO POWER, NO LED (MAINBOARD X541UVK REV 2.0)
przez robgerr • 7 października 2019, 16:25
Good afternoon friends of the forum, this laptop looks completely off. Checking the motherboard I found no traces of oxide or burnt components.
Checking the main power supply of 19 v, I find it at the entrance from the mosfet PQ8901 but at the output of pq8901 I find 0.16v with oscillations. If I remove pq8902 the 19v voltage exit from pq8901. I replaced pq8901 and pq8902 but nothing to do. I measured PU8901 VOLTAGE:
BQ24780S
PIN 1 3V WITH OSCILLATION
PIN 2 3V WITH OSCILLATION
PIN 3 0V
PIN 4 0V
PIN 5 0V
PIN 6 2,66V
PIN 7 0V
PIN 8 0V
PIN 9 0V
PIN 10 0,20V WITH OSCILLATION
PIN 11 0,20V WITH OSCILLATION
PIN 12 0,70 WITH OSCILLATION
PIN 13 0V
PIN 14 0V
PIN 15 0V
PIN 16 0,40V WITH OSCILLATION
PIN 17 0,23V
PIN 18 0,26V
PIN 19 0,25V
PIN 20 0,23V
PIN 21 0,12 WITH OSCILLATION
PIN 22 0V
PIN 23 0V
PIN 24 5,9V
PIN 25 5,8V
PIN 26 0,23V
PIN 27 0,23V
PIN 28 19,31V
Checking the main power supply of 19 v, I find it at the entrance from the mosfet PQ8901 but at the output of pq8901 I find 0.16v with oscillations. If I remove pq8902 the 19v voltage exit from pq8901. I replaced pq8901 and pq8902 but nothing to do. I measured PU8901 VOLTAGE:
BQ24780S
PIN 1 3V WITH OSCILLATION
PIN 2 3V WITH OSCILLATION
PIN 3 0V
PIN 4 0V
PIN 5 0V
PIN 6 2,66V
PIN 7 0V
PIN 8 0V
PIN 9 0V
PIN 10 0,20V WITH OSCILLATION
PIN 11 0,20V WITH OSCILLATION
PIN 12 0,70 WITH OSCILLATION
PIN 13 0V
PIN 14 0V
PIN 15 0V
PIN 16 0,40V WITH OSCILLATION
PIN 17 0,23V
PIN 18 0,26V
PIN 19 0,25V
PIN 20 0,23V
PIN 21 0,12 WITH OSCILLATION
PIN 22 0V
PIN 23 0V
PIN 24 5,9V
PIN 25 5,8V
PIN 26 0,23V
PIN 27 0,23V
PIN 28 19,31V