How laptop power intake circuit works (ways to fix) Lenovo ideapad S145 NM-C111 not charging PART1

explaining how the charger input circuit of a typical laptop works, with drawings to help explain. working on a Lenovo ideapad S145 NM-C111 not charging PART1

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24.4 v

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24.5 v.
It gets 6v from internal ldo. 6v regen pin