This exact issue happened to me as well, word for word how you put it. Took my phone to a repair store and they said the motherboard was damaged and there was nothing they could do. The wording this guide had before was extremely dangerous and probably killed a lot of people's phones.

This section needs to be updated with new photos showing the correct way of removing the battery: using heat. I myself have tried to remove my battery with alcohol, and because of the wording the guide had before, I used too much and my screen and motherboard were completely destroyed.