Lenovo NM-D562 no V on current sensor

[220vdc]

Power supply
Legion 5 pro, nm-D562 rev. 2.0, short search. Test whith power supply 20v. Fuse, first and secon mosfet (pq110-pq111) ok...mosfet pq5401 ok 20v on drain no voltage on source and gate, mosfet pq5402 no voltage at all. current sensor pr5401 R005 no volts. pl and pc around are ok. Many capacitors and pl away are shorted. How can I check if mosfet pq 5401-pq5402 are ok or not? Why resistor R005 is not after second mosfet? Grazie for help

[mon2]

Hello.

1) Remove all power. Meter in resistance mode. Measure the resistance to ground @ P3 label = main power rail to the logic board. What is the resistance in ohms? If the resistance is low = shorted part on the rail, then the DCin mosfets will remain OFF.

2) To check the DCin mosfets @ PQ5401 / PQ5402 -> remove all power -> meter in resistance mode.

Measure the resistance to ground of:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post each measurement. Check both DCin mosfets. Checking for a low resistance = defective mosfet.

[220vdc]

each measurement, PQ5401-2 and boths R005 always 1....may be the capacitor in picture is foulty. I removed chip IT8227...from motherboard because was damaged

[220vdc]

I injected 5v 2A after current sensor R005, standby led is on...near UU6 chip two capacitors (0.1U_6.3V_K_X5R_0201) cu 468 and 469 heat up. How can I test which one is shorted without desoldering? Grazie

[mon2]

Pour a few drops of IPA (alcohol) on only one of these caps. Then inject again and observe the rate of the evaporation of the IPA. Repeat with the other capacitor. If they are heating up, the IPA will evaporate much faster due to this heat. If they are both getting hot then both are defective.

Alternatively, you will need a low ESR (milli-ohm) meter test tool to check the resistance of each of these caps using only this special tool. Should be available on Amazon / Aliexpress stores.

[220vdc]

update, i desoldered SIO. UU9 was short removed too. Again no 20v on PQ5401. mosfet 5401 AND 5402 not short found. Resistance current sensor 400ohms.
test charger IC BQ24780S: VCC20v ACDET 2,6V REGN 5,7V BTST 5,4V NO V ON CMSRC-ACDRV

If I inject 20v on current sensor, led is on...ok 3 and 5 v, other 1,2 v present...Around GPU many capacitor shorted 000ohms