This is probably same issue as I described here: UART no longer works after update
Mine board act like dead but it will start with no UART connection, eMMC and NVME, just SD card. I tried to clear SPI but still no luck getting UART back - it won’t start and no led. I have another rock 3A board and same set is ok on it. As far as I remember updating rockpi3a-rk-u-boot-latest or latest rk-kernel for 3A shows some firmware or SPI updating and problem started on next boot. I tried to clear SPI - but still I’m not sure if that was successful.
@jack - do we have any informations what firmwares can be updated on this board? Maybe it’s something else than SPI? I did not had so much time to reverse eng. those packages but more and more people experience those problems.