I have purchased a new Rock 4A Plus. This model is screen printed on the device also.
I have tried both the Offical Images for Debian and Ubuntu images from the “ROCK Pi 4A | 4A+ | 4B | 4B+” column. https://wiki.radxa.com/Rock4/downloads.
Images were written to micro SD cards using Etcher.
Neither of these will boot. The device shows a solid green light/LED and a blue light/LED flashes with a consistent pattern. Blue light starts as solid then starts flashing after a few seconds.
There are many pages describing the getting started process and it appears that an Micro SD should always still boot.
How do get the board to boot from an micro SD card?