Original post by: Skye Anderson ,
Assuming the new battery was charged some,this means it’s probably not simply a charging issue. It could very well be a power issue on a logic board level. The next step is to open it and see if there’s anything obvious. Do the buttons click right? If opened,see if any components look black and burned. It very likely is a power management issue(maybe even the chip). The only way to fix this is opening it up.