I'm having this trouble too. Mine is the new 4K model, powered through a USB3 hub. I've tried 65w chargers, 5v 20w power supplies (constant voltage) with no luck. Eliminating the USB hub doesn't seem to change anything. TV will turn on and I can cast to it from my phone, but no signal. Reseating the hdmi does nothing, not a flicker. Power cycling the device with the cable fixes it every time. But it happens daily, sometimes more. I need a fix.

I inherited a Pixelbook from my roommate who's bedroom was covered in coffee. I mean everything, top to bottom. This machine would have been perfect for my new job but the keyboard has patches of dead keys. There is also a nasty impact on the top corner behind the screen, but I'm leaning towards coffee as the culprit. Waiting for my ifixit kit to come in and I will dig into it. It was free so I've got nothing to lose. If any of you find a solid teardown to the keyboard, please link me. Update (11/28/2020): Okay, I've done A LOT of digging into this one now and I think I see the problem. It is not a software problem. After ripping off the layers of plastic they hide their keyboard in, I exposed the only slightly dirty inner workings. Looks like the little leads coming off each of the keys experienced corrosion. I'm wondering if it has to do with the choice of materials since I'm seeing people losing their keyboards so often in the forums. You can see a normally functioning key with clean white leads running...