There could be many factors on determining what is wrong with your device. The two main concerns is that the battery isn't that effective or the motherboard and the charging port was disrupted and something shorted it. I think the only thing you could do without knowing what to do is to replace the whole computer, since the battery was replaced and still not working, and motherboard replacement could be expensive. Replacing the laptop means that at least you know you could get a new laptop without any issues.