After replacing display, iPod won't power up. What can I do?

Some time ago I dropped my iPod touch in water. I placed it in rice for about a week and eventually got it to work again. There were only a few problems:

-The up button on my volume control was faulty. Didn't respond to the press and would sometimes start going up on its own.

-Random performance issues causing the iPod to restart or turn off.

-After a week or so, the backlight of the iPod went dead.

I decided to open the device and see what I could fix. I bought a replacement display online, replaced it, and now my iPod won't power up. To be clear, I plug the iPod into my computer, the computer doesn't register that a device has been plugged in, and the screen stays black. I've tried using different iPod cables, different USB ports, and leaving the iPod connected for long periods of time to charge the battery. I've also tried clicking the home and lock buttons to try and turn it on.

Anyways, I'm not sure what could have gone wrong here. I'm not sure if this is just a side effect of dropping the device in water or if I accidentally wrecked something when I opened the device. I tried to be quite careful, but is it possible I cut a ribbon cable or something similar?

Other actions I performed while the device was opened:

-used canned air to dust the inside of the iPod (there was lots of dust and gunk that had accumulated on this inside)

-used rubbing alcohol and a paintbrush to clean off gunk and dust stuck inside the device

Any point in the right direction or ideas on where to look for damage would be very helpful. Thanks.