Another possibility came to my mind - the MP2979A controller i replaced for new one (from Aliexpress) needs to be programmed to set proper voltages?

Some sad progress here - after replacing all DrMOSes still measuring 19V on all of them. Cleaning/increasing hole did not help...

It seems, You were right!
Removed all of them one by one, then replaced one and it produces correct voltage! Maybe all of them were partitially shorted...
During the weekend ill try to solder rest of them and check if CPU is alive

Thank You one more time!...

Hmm, i measure same 19V on all phases, so it seems i really missed some layers shorted when grinding burned hole...
Really happy
Thank You!

ok, ill try to remove them one by one and see.

Thank You very much!

Hello again,

trying to repair it in my free time even if it will require CPU replacement. Doing it for my own education...

Already "cleaned" burned hole and replaced affected components around + replaced MP2979A chip.

All shorts resolved, battery charging is working, all voltages present (EC and GPU is warming up when charger is connected), except one serious problem - on CPU VCC rail (coils) i measure (almost) main power voltage - see pictures.

May i please ask some experienced with this type of power supply knowledge, wht can cause...

Thank You, although this is not very optimistic news

Hello,

I'd like to ask someone more experienced than me for advice - I'm trying to repair this Legion Y540 with a burnt mosfet (PU3001) through the PCB (damaged/shorted capacitor was also on the other side).

I am able to drill out the damaged part of the PCB, repair the surface paths and solder the components according to the available Board view data, but it is very difficult to find out if some internal paths are broken.

1) Any chance there is/will be CAD documentation available for the PCB layers for this Lenovo, such as for example for the Dell E7470...