Sony Experia L3 power issue

Customer brought this phone to me, had water damage and gave no life with or without charger, I took it apart cleaned both main board and charger board down with 99% isopropyl waited for it to evaporate then reassembled, plugged charger in and gave me a solid red light top left of phone, no power on though. I tested battery directly for voltage and it gave 4.16 V as shown in picture but the voltage test pads on the board only showing 0.4 with battery. But when I plug the charger in it gives me 4.2V on the board test pads why could this be?