MSI GS73 (MS-16K61) : help me find short (got thermal cam)

[snow_sg1]

Hi,

First : I've got a SMD rework station, thermal camera and good soldering station

This is my first "short" motherboard repair, this laptop was 25€ so no loss, it just for learning. I want to learn how to fixed board because I want this to become my job.

I've been fixing electronics for 15+ years, but mostly VCR and camcorder.

So, I checked power adapter pin to ground, no short, then I plugged the charger in, light on charger blink indicating short.

PQ19 mosfet got HOT straight away (viewed on thermal cam). Checked, it is good. PQ20 (other mosfet) has dead short (0.2 Ohm) between pin1 (SDC IN+ and GND).

Checked CPU/GPU and their mosfet, seem fine.

Injected 0.9V/2.5A at pin1 of Q20

The only thing I can see getting slighty hot (32c) on the board is PU6 (NB685 buck converter) => It's creating 1.05VSUS that then goes to creating 1.05U_VCCST & 1.05DX_VCCSTG for CPU Power

I've tried remove the two caps just below this buck converter, not the issue.

Before de-soldering this chip, am I going in the good direction ?

Thanks,

Best Regards

Nicolas

[snow_sg1]

I've removed the chip, now I got 150 Ohm instead of 0.2 Ohm between pin1 of PQ20 and ground, it still seem low ? Is it worth replacing this chip ? Thanks
PS : When I plugged the charger it doesn't go into short