I solved the boot problem by using a different SD card.
Not resolved is the black screen problem. I tried all the DRAM patches for Manjaro Phosh and Mobian from 492 to 624 MHz and had more or less success. No patch makes the phone stable. I also bought my son a Pinephone and both came together in one delivery. His phone is stable from the start, so I suspect that the memory chip quality is poor on some devices? Selling an unusable device is not good business. The quality control should definitely get better.
I have no idea. What else could I do?
Not resolved is the black screen problem. I tried all the DRAM patches for Manjaro Phosh and Mobian from 492 to 624 MHz and had more or less success. No patch makes the phone stable. I also bought my son a Pinephone and both came together in one delivery. His phone is stable from the start, so I suspect that the memory chip quality is poor on some devices? Selling an unusable device is not good business. The quality control should definitely get better.
I have no idea. What else could I do?