@setifstar:If the display stays at boot, the USB kernel starts but cannot read rootfs.img. In my experience it is very hard to find a USB stick that works 100% of the time. Usually I have more success after several power ups: sooner or later the kernel does not switch off the USB power and the whole lot starts up. Use older USB sticks of 512 MByte to 2Gbyte in capacity to get the best results.
@sadaghiani: If have tested the flash version and it flashes perfectly, it also starts up the way it is intended. My gut feeling says you are trying to flash the USB uImage into flash memory: this will not fit and indeed yield a correct Err 0x70. Please read the installation instructions carefully.
Regards,
Audioniek.