Thanks @ firestormmedia, that was the only solution that worked for me. I unscrewed the motherboard and lifted it up, thus disconnecting the battery and effectively removing the battery. After than, I assembled the iPad back together, and everything worked.
On a related note: I was using metal tongues to put the wires/chords into their places, which may have caused this problem. I recommend using fingers instead of anything metal to reconnect the wires and cables.