Yes, looks like it is not a malf problem but something else.

So, if you have not been able to flash the device, I assume it has the original content full in there, right?
First I'd take of course backups of all partitions, before attempting anything. Usually tar works best as dd'ing the devices will create so large images as to be unnecessary.
Then, I'd investigate what is the boot phase it hangs on, and for that the absolutely best tool is to enable serial console and monitor that when the device boots.