On my new battery the connector was not aligned precisely so the battery was not connected properly to the motherboard after screwing it in. The connector is supposed to hold on it’s own without the screws. If the connector does not hold to the motherboard without the screws, make sure that the connector is actually plugged in properly and only screw it in once it holds by itself.
I have just successfully replaced the battery in my HTC One M9, yay!
Beware: On my new battery the connector was not aligned precisely so the battery was not connected propery to the motherboard after screwing it in. The connector is supposed to hold on it’s own without the screws. If the connector does not hold to the motherboard without the screws, make sure that the connector is actually plugged in properly and only screw it in once it holds by itself.
I did not know this 15 minutes ago and thought i had destroyed by phone, but it was just a loose battery-connector. :-)
