I disabled a gpu that freezed randomly by taking out gpu's power supply mosfets in a ba41-02176a samsung mobo, I dont remember if a took out vram PS mosfets too, most likely I did

hello friends, I have a DELL LATITUDE 5420---MODEL P137G, ST 20TFKN3 LA-K491P REV:2.0 (A01) and its quite a challenge. It powers on with the battery disconnected, lasts on for about 15 secs, and then shuts off. It does the same with battery only (no adapter). With battery and adapter it sometimes starts after hitting the button several times. It displays nothing in every case. Since only the Boardview is available, I guided myself with schematics similar to this laptop (I'll add them down).Some measurements:

1- After receiving power SIO_SLP_S0# goes high and never changes.
2-every...