This usually happens when the hinge isn’t aligned correctly after the shell swap. Even if the screen and LCD are re-seated, the top housing won’t close or sit flat if:
1. The hinge barrel isn’t fully rotated into its locked position.
It needs to “click” into place. If it’s off even a little, the lid will resist closing.
2. The ribbon cable has tension or is twisting inside the hinge tunnel.
A slight twist is enough to keep the top shell from lining up.
3. One of the hinge tabs isn’t sitting in the shell track.
The system will close on one side but not the other.
Quick fix:
Open the system back up, rotate the hinge fully until it locks, check that the ribbon sits smoothly with no sharp bends, and then reassemble.
No new parts needed unless the hinge barrel is cracked.
If you want, I can tell you exactly how to check alignment step-by-step.