i’m seeing you battery doesn’t seem drained, so i think thats not the problem… how many amps is you switch consuming while charging…
My USB multimeter broke so I have no idea but the fact that it is showing the battery’s level on the screen like you said means it’s prob fine
You need many tools and spare parts, as i’m seeing you don’t have them so it’s going to be almost impossible to fix it whitout those…
i have same issue i tear down my switch and capacitors near wifi chip are shorted