Hi,
okay, I have managed to flash the Jetson Nano P3448-0002 emmc + with my custom carrier board successfully, it took only 2min now. It was the USB cable, my colleague has exchanged this. It was not of good quality.
Note: https://forums.developer.nvidia.com/t/flash-xavier-nx-emmc/154548/5
Now we can continue with Jetson Nano P3448-0002 emmc and HPD.
thank you…