After replacing my screen, the logic board is overheating.

We are just volunteers helping people fix their stuff.

It’s possible that the replacement screen is causing the battery drain issue (which in turns, heats the board). In order to test for that, you could try to re-install the original screen. If the original screen works fine without overheating, then the issue is with the replacement screen. If the replacement screen came with the Front Camera/Sensor flex pre-installed, I would try to reconnect the replacement screen without connecting the FCAM flex. Some of those “included” small parts can be unreliable. Please contact iFixit support if any parts need to be replaced.

If the original screen also has the same issue, then you may have damaged the logic boar during the repair. You will need to inspect it under magnification to see if the connectors are damaged or if any tiny components were dislodged.