Hi
Given that you did get it to partially boot with a new screen it points towards either a poor contact, so disassembling and reassembling may ‘work’ ~ you could just try replacing the screen ensuring you have good contacts.
In case it’s a contact issue be sure to clean what you can with isopropyl alcohol and when tightening the screws do around the display first not to tight then the rest then tighten them all but not too much.
Check the water ingress indicators, as if one is red you will not be able to use any warranty you may have.
See this post that shows the ‘red’ square, hoping yours is white