Replaced top case, now does not power on

Hey guys, I'm performing a repair on a Macbook Air 13" 2010.

Original issue: Certain keys on the keyboard did not work or responded erratically due to small amount of liquid damage.

New issue: Replaced top case, now the computer does not power on. The battery indicator LED does not light up unless I plug it into another computer first.

Sometimes the computer will power on for a few seconds and the fan spins at full speed, but then immediately powers off.

I tried again with the old top case and the computer still does not power on.

I reset SMC and tested with the battery unplugged and did most basic troubleshooting..

Could this be the magsafe I/O board?

UPDATE: The computer powers on if I jump it from the logic board power pads. Immediately the fan spins up really loud and does not stop spinning at full speed. I can jump the power pads with no magsafe plugged in, but the OS states that there is no battery connected, although it is obviously running on battery power.