Asus A551L - S551LN REV 2.2 - doesn't turn on

Hi,
The laptop worked but stopped working after cleaning. there isn't on the board any voltage. No voltage on the switch. I checked the resistance on all coils and I didn't find short circuit.
PL8100 - 130ohm
PL8101 - 6k ohm
PL8001 - 47ohm
PL8201 -2,5 ohm
PL8801 - 6,4k ohm
PL8301 - 360 ohm

Motherboard don't consumption current. What i can check?

Hello!

Measure the voltages to ground on pins 1, 4, 8 of transistors PQ8801, PQ8802.

I did measurements:
PQ8801
1 - 20V
4 - 20V
8 - 24,8V
PQ8802
1 - 20V
4 - 20V
8 - 24,8V

The voltages on transistors are normal, but you counted the pins in the reversed orientation.

- Measure the voltage to ground on pin 5 of charger chip PU8800.
- Measure the voltages to ground on pins 2, 4, 6, 7, 11, 12, 14, 15, 19 of chip PU8101.

Sorry, I wrote it illegibly. Char (-) means a hyphen, not a minus.

PU8800:
5, 0V
PU8101:
2, 0,09V
4, 0,09V
6, 0V
7, 0V
11, 20V
12, 0V
14, 0V
15, 0V
19, 0V

Mimek написав:Char (-) means a hyphen, not a minus.

I know, but you count the pins of transistors in wrong direction.
And the power supply for this board should be 19V, not 20V.

- Measure the resistance to ground on pin 5 of chip PU8800.
- Measure the resistances to ground on pins 14, 15 of PU8101.

Please, post a clear picture of chip PU8101 board area with a nearby surroundings.

5 of chip PU8800: 0,94 Mohm

PU8101:
when I put the red probe to the ground:
14, 35kohm
15, 29kohm
when I put the black probe to the ground:
14, in Mohm and the resistance jumps between 50Mohm and 5Mohm
15, 12 kohm

- Measure the resistance to ground on pin 12 of chip PU8101.
- Measure the voltages to ground on both pins of resistor PR8114.

Pin 12 of chip PU8101: 6 Mohm

Resistor PR8114:
on the PU8101 side - 18.35V
on the other side - 19V
I think I made a mistake in my earlier measurements, on pins 12 of chip PU8101 is 18.35V

Mimek написав:PU8101:
14, 0V
15, 0V

Are these two measurements correct?
If so, replace the PU8101 (RT8239B).

Replaced PU8101 and no changes. I repeated the measurements and they are the same

- Are you sure there is 19V on pins 11, 12 of chip PU8101?
- Are you sure there is 0V on pins 14, 15 of chip PU8101?

If so, open (cut) the jumper PSL8100 and remeasure the voltages to ground on pins 11, 12, 14, 15 of chip PU8101.

I cuted jumper PSL8100 and
PU8101:
now:
11, 19V
12, 18,3V
14, 5V
15, 3,3V

Should I perform a short circuit test at 3.3V?

Measure the resistance to ground on jumper PSL9101.

the resistance on the PSL9101 jumper is 3Kohm

- Measure the resistances to ground on both pins of jumper PSL8100 (jumper opened).
- Measure the resistance to ground on pin 3 (central pin) of diode D2201.

PSL8100
pin 1 - 0,6 Mohm
pin 2 - 78 kohm

D2201:
on pin 3 - 1ohm

Mimek написав:D2201:
on pin 3 - 1ohm

It's a short circuit to ground.
Perform a short circuit test on pin 3 of D2201. For a short circuit test limit the voltage to 3V.
The PCH part (small core) of the APU hybrid is unfortunately very likely damaged.

I made a short circuit test on pin 3 of D2201. Only the PCH gets warm. So PCH is damaged. Thank very much for help in solved problem