No power - Mosfet ? ? on Lenovo - IdeaPad 3 17ITL6 - Motherboard HS760 NM-D473

[samstown]

Hello

I've got a Lenovo that stopped working. No sign of life at all. I was hoping it would be an easy fix but I am not sure it's mosfet, I think resistance should be low but it's OL.

Thermal camera show MOSFET heartbeat.... It's Sinopower SM4377.



Thanks
Sam

[mon2]

Fault could be that the actual load being switched by the mosfet is shorted or drawing more than normal current.

Remove all power / no battery. Measure the resistance to ground of each pin (source / gate / drain) on this mosfet that this throbbing on the thermal camera. Post each measurement in ohms.

[samstown]

Thank you for your answer.
Drain to GND = 50 Kohm
Gate and Source to GND = OL

[samstown]

I see 20.4V going to a little cap or filter and nothing on the other side.

[samstown]

Can't find schematic here. i'll keep searching.

[mcplslg123]

NM-B452 is similar.Refer to this schematic.

[samstown]

thank you. I wll check that.

[samstown]

It was the backlight chip causing the problem

[kurzweil]

Hello. Can you please tell me what name this component has?

[SMDFlea]

Hello. Can you please tell me what name this component has?

Can`t see the part numbers or logo, the image is too blurred

[kurzweil]

Can`t see the part numbers or logo, the image is too blurred

Yes I know. the photo is from samstown. The part melted in my Lenovo. I can no longer recognize what name the chip has.

[kurzweil]

Hello

I've got a Lenovo that stopped working. No sign of life at all. I was hoping it would be an easy fix but I am not sure it's mosfet, I think resistance should be low but it's OL.

Thermal camera show MOSFET heartbeat.... It's Sinopower SM4377.



Thanks
Sam

Hello Samstown
Can you please tell me what name this component has?