Chosen Solution
I did a battery replacement, and the phone powered up, but the display wouldn’t come on at all, and I saw the “leaked ink” behind the glass, so I got the digitizer/display assembly, replaced it, put everything back, and now there’s no power at all. Any suggestions on what I might have messed up?
Did you disconnect the battery during the screen replacement process? Need to be careful of Static Discharge, which is something people forget. A small amount of discharge can easily damage the phone. The other possibility is the LCD/Digitizer may be defective, unless you have another unit to test it on. Last option is the board, whether there was a shortage or not, if the phone was dropped there is a chance that the boards power system may be at fault. So if you turn on your device and you can hear it, you know the screen works, 100% tested, then power may not be properly distributed. Good luck, wish the best