Hi guys,
Yeah, I'm late to the party and probably too late to help you, but on the off chance this will help someone else, I'll throw in my $0.02 worth.
I read through the article @wseltzer posted, and it sure looks bleak. I did see a couple of the posts referred to something similar happening to a Pixel 4 and a 4XL, so I'm going to go ahead and repost the similar experience I had with my niece's 4XL. No idea if it'll help, but here it is.
[quote]This sounds suspiciously like what happened to my niece's Pixel 4 XL. Wouldn't charge, can't reset, no power, just looking dead.
I checked everything possible outside the phone and tried every suggestion I could find on the internet for resets, button presses and chanting "Wake up!" to it, with no luck.
I resigned myself to opening it up and taking a look around. For safety's sake I unplugged the battery and checked the connector and looked carefully at everything for any possible clue as to what was going on, but found nothing.
So imagine my surprise with I plugged the battery back in and pressed the power button only to have it turn on!
I literally did nothing to the phone but unplug the battery for a while then plug it back in, and all of the sudden it's working again. I tested it every way I could think of, charging it to full then running it till it died a couple of times, and it worked exactly the way it was supposed to.
I have no explanation for this miracle cure other than thinking that something in the software got royally messed up and crashed the whole thing to the point where it couldn't even reset itself and that disconnecting the battery finally reset it so it could reboot. In theory it shouldn't be possible to lock out the hardware (hard) reset function, but I don't know what else could explain it.
If you're patient you could just wait until the battery dies completely; that should accomplish the same thing as unplugging the battery, but given the long battery life of those phones, I suspect it will take a very long time to drain.
So my suggestion is to open it up and unplug the battery. Give it a half hour or so - you probably only need maybe 30 seconds, but that's how long I had the niece's unplugged so that's what I'm sticking with - then plug it back in and see if it'll wake up.[/quote]
The only difference here is that I never tried plugging it into a computer so I have no idea if it would have showed up there or not as it does with the majority of the other users who experienced this problem. The phone is working now, so I can't check it for you, sorry.