Leo took his multimeter probes to the board. Pin 4 of the charging IC should have been sending a "gate" signal to let power through. It was at 0V.
Because these codes are used across different laptop motherboards, the exact schematic you need depends on the OEM model number Hannstar J Mv-4 94v-0 E89382 Schematic Pdf
(If you want search suggestions for related terms, I can provide a few relevant keywords.) Leo took his multimeter probes to the board
This is a UL (Underwriters Laboratories) flammability rating. It indicates the board's plastic material is self-extinguishing within 10 seconds. Hannstar J Mv-4 94v-0 E89382 Schematic Pdf
Cleaning and replacing corroded components by identifying their original values.