After replacing the surface pro 4 LCD, it won't turn on the battery mode unless i plug it with the charger

After i had replaced a surface pro 4 LCD, won't turn on battery mode unless plug it.

Before taking off the broken screen the pro was working good just the screen was broken, so i turned it off then started working on it. after taking off the old broken screen. i tried to connect the new LCD on to test it but no response at all.

it does only work when i plug it in the charger and it does show me that the battery is 100% full on the screen?

also i did put a piece of paper between the connects part for the battery and the motherboard. it does show me an X on the battery icon on the screen when i turn it on

but i couldn't resolve the problem for 1 week now and i have been searching online but no one has had these issues before.

so how can ifixit ??