So if You plug it in it does nothing right? Not even vibrate or anything, dead? I did have a 4a and I "refurbished" it by changing few things and the battery to new one, then it died (first couple of hours it worked great and had a great battery life but after fully charging it and leaving for a single night ~ 7 hours it completly died, used multimiter and battery was at 0v) and showed no signs of life. I thought it was dead in a hardware terms but I changed the battery to the original and it started working as nothing happened. As it is also 4a i suspect dead battery especially if it was not used for some time, I can't say for all pixels (somewhere I read an article that they all react the same being unresponsive, something like Iphones stay on apple logo and just bootlop but it was at the time that pixel 6 lineup was new so you know...) but for 4a if the battery dies then phone gets completly unresponsive. I would suggest changing the battery, it won't hurt if it's already dead. I just can't explain the anomaly of unresponsivness after updating but I am 90% sure that in it's current state it is the battery fault.