Can a failed device that has an error loading the FPGA configuration be repaired utilizing an identical working device that works properly?
These units are centered around an FPGA, and they attempt to boot with a correct initial sequence, but fail to fully boot.


An FPGA that is failing to load its configuration will usually not enter a running state.

The symptoms you're observing suggest that either:


The FPGA is self-configuring correctly, but is not entering a functional state afterwards for some reason (which may be caused by a hardware failure in the FPGA, or in another part of the system).
The boot process you are observing is driven by another controller which is failing for some reason (which may or may not involve the FPGA).


While it is possible that the problems you are observing are caused by a loss of FPGA configuration data, it is unlikely -- and it is even more unlikely that you will be able to successfully copy this data from another working device. If you have the option to return the devices for a refund, I'd pursue that option rather than attempting repair.