HP SPECTRE X360 Convertible Model 13-ae019nl motherboard DA0X33MBAF0 rev f. no power

This Laptop doesn’t turns on.
Connecting PSU voltage on connector 20V but after 5 second drops down to 0V and soon increase 20V again and goes on continuously.
I can’t find schematic I didn’t find any clear short and no components become hot.







Coils with resistance to ground of 43K ohm are shorted each other

0,015 A




I checked voltage of 5V on coil marked 5V for 4 o 5 seconds but the coil of 3,3V ? ( I suppose) reach 0,5V and then 0V.

1= 1,5V for less than 1 second
2= 12,6V
9= 0V
11=2,9V
12=3,3V first on= less than 1 second
second on 3,3V 2 seconds and go on same way
14=0,5V less than 1 second
17= 0,5V first on 0,5 less than 1 second
second on 0,3V for 2 seconds and go on same
way

All other voltages stay on for 3 seconds

14 = slowly up to 16K ohm
17 = 4K ohm

Hello
After replacing SY8286BRAC led near dc connector turns on but SY8286BRAC becomes hot and after 10 seconds led turn off.
I have no try again to avoid chip damage I can’t find any short near.

A= rise up to 40k ohm
B= rise up to 230K ohm
C= 3k ohm
D= 4k ohm

0,33 A

There is not a hot component, only a little warm on CPU and DDR zone

Only component clearly warm is CPU because I touch it over, but all area around CPU become a little warm but all very little warm.