Ok, I don’t use etcher - I found it was not good, but that is just my opinion. I use a linux machine and just use disks to write the SD cards. I use this for the cerbo, Beaglebones and Pi’s. with no problems. - well almost. Disks will not properly unzip the archive before writing it. This can also cause the error you are seeing.
so: Unzip the archive using a standard program, then format the sd card using an image writer that you know is good. then try again.
by debug access: If you have the skill level there is a serial console port inside the cerbo where you can see the boot process go on via a serial terminal. If this doesn’t make sense to you, you can look this up using other small computers - eg beaglebone as an example. I was assuming that you had this given the messages you quoted above, but the debug access has a lot more detail. How did the Cerbo get bricked?
OK, clear! I should be able to get that working and will try another imager-tool. Else, it’s just a warranty claim as this cerbo stopped working during the night. No changes, no updates, nothing else.
Tried different ways but to no reveal. Replace the unit with a new MK2 device and all is working again. Old unit has been returned for repair/replacement.