No display after screen and battery replacement

I recently ordered from iFixit three items to repair my apple watch. Battery (just was not holding a long enough charge), force touch sensor and used sapphire screen (screen was shattered from a three foot unlucky angle drop). After installing all three without any issues (no torn cables, took about 30 minutes), I get no display.

When I charged my watch for about 1 hour the battery gets warm (the actual battery not the whole watch). Seems about as warm as is normally the case. I have tried putting the old screen on and the old battery back in with no luck. I have tried hard resets (holding crown and side button for up to a minute) . Nothing is working and nothing looks even slightly damaged. Am I out of luck? I throughly read through iFixit instructions before starting.

This is the first gen device. Series 0 or revision 1. As a side note I have successfully repaired at least ten iPhones; screens, batteries, cameras and even a proximity sensor (very small parts). One time I even tore apart a water damaged iPhone 4, cleaned all the parts, including the logic board with isopropyl, and had it running for a year.