Chosen Solution
I assume that there’s a battery temperature sensor that did not get properly reconnected, but I can’t find anything that would tell me where to look. The watch is fully charged. I can turn it on, but within 15 seconds, the screen says “Watch turned off to cool down”, and then it shuts down.
Alright, I have a probable answer. I took the watch apart again, and the connector from Step 4 wasn’t seated properly. 🤦 When I reassembled the watch the first time, I thought that maybe, since they lined up when I put the two halves back together, they would make a firm connection, but they did not. When I took the watch apart again to investigate, the connector was clearly not attached. I reattached it firmly, reassembled the watch, and powered it back on. The watch stays on now, so I’m pretty sure that was the issue.
