Chosen Solution
I tried changing the battery in my iPhone 4 a few years ago. Accidentally tore the battery away from the connector due to the flimsy little tab that connects them. The phone would come on briefly while plugged in, showing the white apple logo, then turn off and on again. Recently ordered a new battery and installed easily tonight. Number one, it doesn’t fit because that same flimsy little tab is too long and would have to be bent. So I attached the connector with the screw and can’t replace the back of the phone because the battery is partially sticking out. I’m afraid if I bend the tab to fit the whole thing in I’ll break it again. Anyway, phone still won’t come on and does exactly the same thing when plugged in. Shows the white apple for ten seconds then turns off. Rinse and repeat. What do I do?
Unless you have a good magnification or tremendously good eyesight you won’t be able to see much, but battery socket may be damaged and should be inspected carefully. If both batteries, old and new, don’t charge at all as it seems, chances of a physical damage are there.