MSI PULSE GL66 motherboard MS 15811 ver: 1.1 charging issue

Actually I didn’t find any schematic.
This motherboard works with power supply only.
It comes with BQ 24780 replaced by someone and I have to fix some pads.
Mosfet missing in the picture goes shorted just connect the battery.
Seems not component shorted.

Hello!

Your board seems spilled - some components are corroded:

All corroded components must be replaced. Check the whole board for more corroded components.

Hello
I replaced corroded parts.
How can I test mosfet zone, because I can’t insert mosfet and it goes shorted every time.

Replace both transistors - PQ36 and PQ37 regardless of whether one of them seems functional or not.
Then measure the voltages to ground on all pins of battery connector and on pins 1, 4, 5 of transistor PQ33 in the following cases:
a) Power supply connected only (without the battery).
b) Battery connected only (without the power supply).

I replaced both transistors
Battery pin with battery connected

Pin 1-2=9 ,63V
Pin 3= 0V
Pin 4= 3,3V
Pin. 5= 3,3V
Pin 6= 0,3V

PQ33 Mosfet pin Battery only

1-2-3 =- 9,63V
4= 0V
5-6-7-8 = 9,63V

With power supply only motherboard auto power on.

Battery pin

1-2 = 0,33V
3= 0V
4= 3,3V
5= 3,3V
6 = 3,3V

PQ 33 Mosfet pin power supply only

1-2-3 = 19V
4 = 19V
5-6-7-8 = 0,33V

Replace the battery.

Should the circuit be ok?

Yes, it seems the board is fine.

Ok laptop now works with battery, but after connecting power supply mosfet is shorted again.
Now is shorted after 3 minutes with battery and PSU connected.

Please, post a clear picture of marked area of the board:

I have rebuild this line from chip to gate of PQ37 as I didn’t find right schematic I found it to a similar schematic

The marked three components seems corroded and needs to be replaced.

Ok
I replaced corroded components and shorted mosfet
Now how can try motherboard to avoid damaging mosfet ?

Measure the following resistances:
a) Between pin 1 and pin 2 of charger chip PU5.
b) Between pin 19 and pin 20 of charger chip PU5.
c) Between pin 23 of charger chip PU5 and pin 4 of transistor PQ37.
d) Between pin 26 of charger chip PU5 and pin 4 of transistor PQ36.
e) Between pin 27 of charger chip PU5 and coil PL21.
f) Between pin 28 of charger chip PU5 and cathode (-) pin of diode PD1.

Between 1 and 2 of PU5 =3ohm
Between 19 and 20 of PU5=1,7 ohm
Between 23 and 4 of PQ37 = 0 ohm
Between 26 and 4 of PQ36 I had to remove solder mask
I found the wire that I had solder disconnected but maybe removing solder musk.
If it was disconnected could be it that makes mosfet shorted?

Between 27 and PL 21= 0 ohm
Between 28 and cathode PD1= 10 ohm

valieromarco wrote:If it was disconnected could be it that makes mosfet shorted?

Yes, definitely.
All other resistances seems fine.

Hello
I have rebuilt all connections and finally it works.
So maybe problem was missing connection between pin 26 and pin 4 of mosfet.

In that case mosfet was shorted because mosfet contacts were closed and 19V of PSU and battery voltage were in contact?

I have to try notebook with OS, but I can’t find on the bios CSM /Legacy
It is setting on UEFI and is no possible to change

Its customers disk?
Why you need to go legacy mode?
Its 11th gen of intel.

No customer bought notebook as faulty and old owner keep his M2.
I installed my M2 but bios is setting on UEFI MODE

valieromarco wrote:In that case mosfet was shorted because mosfet contacts were closed and 19V of PSU and battery voltage were in contact?

In your case, the gate pin of the transistor was not connected and acted as an antenna - as a result, a charge appeared on the gate of the transistor, which partially opened the transistor. It entered the saturation region.

valieromarco wrote:I have to try notebook with OS, but I can’t find on the bios CSM /Legacy

It's a newer laptop, where the "Secure Boot" is enabled and the BIOS may be permanently set to UEFI mode.