I just got my rockpi 4b with emmc module. I have a 128 GB micro ssd, which I flashed with stock image found on site. Flashed using etcher.
This is the ssd card
and this is my USB charging cable.
I also have a USB C output from my laptop docking station.
emmc connected but no ssd : I see a message on my monitor telling me to install os on emmc
emmc conneced and ssd : if I use AUKEY charging cable, green led goes on for two seconds, goes off, then goes on again and is solid - no flashing. Screen is black. If I use the laptop docking station, the green led goes on and stays on - does not turn off. But screen is still black.
With emmc and ssd removed, and rock pi cabled to my pc using charging cable to usb c, when I run
lsusb, I don’t see any entries for rock pi.