Check the battery boards data cable connection. Reference Steps 10 ~ 13 in the [guide|133428] guide. Often I find the ZIF latches are not folded down to compress the cable or it’s missing! As it flew off when you unlatched it or broke things.
I would install this Gem of an App [https://www.coconut-flavour.com/coconutbattery/|CoconutBattery] it will offer useful info to diagnose things. Post a snapshot of the apps main window here for us to see.