flashing apple logo after new screen installation

There are a few of possibilities here:

1. It could be a bad replacement screen. Try installing the original screen to see if the problem goes away. If it does, then you probably have a bad replacement screen.
2. It could be damage to the Home Button or Front Camera Flex. Take a close look at the flexes and connectors, preferably with magnification. If in doubt, just connect the screen alone without the FCAM or HB. The bootup will take longer but once booted, everything else should work.
3. You have logic board damage. This could be caused by accidental damage during the repair or latent issues that only crop up after repairs and the requisite shutdown and reboot, such as the Audio IC or Baseband. If you have a short bootloop (~10 secs) it’s usually the Baseband IC.