Need help/ideas to fix a Asus K401L

I got it from the recycle from my work and wanted to see if it still works. It wouldn’t turn on and it didn’t have a power supply. I made a makeshift one bc I don’t want to spend money on it if I don’t have too. The charging light comes on but only at certain angles. And it won’t power on. It could be the power supply but it’s the same voltage and a little higher amperage that the laptop needs and the plug in peace I soldered on fits fine. I can’t take the battery out with out having to take the entire back cover off. I tested the battery with a voltmeter but idk if I did it properly. I would be grateful if anyone has a way to fix it or any ideas that might work.

Thanks in advance