I reflashed SD card from the downloaded image, so it should be OK. I just followed this guide in first post, so wiped former SPI flash, reboot, connected PBP to PC and made all the commands and all of them finished OK.
I first see red dot, then green dot and blank screen with backlight.
I have no idea what happened.
It might be a myriad of things. But try to recover by entering maskrom mode.
I suspect you didn't erase your flash completely.
One more question - did you disconnect all of the boot devices ?
I think its sd -> nvme -> usb -> emmc
I erased that flash using the command supplied in the first post. I had not connected any of boot devices except NVMe and eMMC in PBP. Should I disconnect them too?
I tried boot also from USB using SD to USB adapter, but the result was the same. Blank screen with backlight.
Thanks for the wiki link. Just tried from another computer and same issue. All dependencies are installed and up to date, but I'm going to take your advice and hold out for a while. For now, I'm still pretty happy just being able to have my home folder on nvme.