Boot failure

RS232 port only displays the following after flashing 2.8 Angestrom on a previous Torizon 5.0.0

Industrial temperature grade DDR3 timings, 64bit bus width.
Trying to boot from MMC1

Industrial temperature grade DDR3 timings, 64bit bus width.

How do i recover?

Please load Toradex Easy Installer from USB OTG as described here.

We have no prompt to enter commands. the Boot process stop there and does nothing more.

You likely will actually need to read the contents of the link @alex.tx sent you, ok?