I followed these installation instructions to install Phosh on the eMMC.
I used popsicle as the flasher. I’m retrying it with balenaEtcher, same result.
Phone won’t turn on at all.
It’s basically a brick, although I can still boot Jumpdrive from the SD card.
What could I be doing wrong?
Are you sure you downloaded the correct image for your device? The (original) PinePhone and the PinePhone Pro require different Manjaro images.
Also note that the images come in compressed .img.xz form and should be uncompressed before flashing (unless your GUI tool does that automatically, but I would rather manually uncompress it to be sure).