any one have experiance rebuilding nintnedo advance sp's?

so heres my deal I have 3 consoles
1 that had a dead battery
1 that had a broken shell. (otherwise worked fine)
and 1 that had screen problem.

I was an idiot and took all 3 apart before I knew what was wrong with the 1 that had a dead battery.

now heres my problem putting them back together I made sure not to damage any of the screen ribons at alllll. but the first time I put 1 back together using the broken shell sp parts and the sp with screen problems the rusults where this
would power on but no audio or visual

took it apart and used the other screen from the sp with the dead battery and now I get sound but no visuals.

Idk wtf could be wrong. Ideally I should have just switched batterys with the sp that wouldnt power on to see if it had any other problems but this is the first time Ive takes sp's apart so I fucked up lol. but Atleast 1 of the combinations should work perfectly so idk what happened. any suggestions? any frequent problems anyone has come across when putting them back together?