Battery issue leading to motherboard change out.

Hey guys, I need some help please, any help will be greatly appreciated. So i picked up one of my friend iPod Classic to do a battery repair. The battery wasn't holding a charge therefore i swapped out the battery and still it would die very fast. I confirmed it was something with the logic board there fore went onto ebay and purchased a new one. after swapping and reassembling for some reason when I attempt to close up the iPod the ipod shuts off. Any IdEaS?