Can you private message me the service tag? Did it work on older builds?
This is the same issue I found and reported with build 0A62 for the 7020. Suspect that updated BIOS (2.0F) would not allow Merlin to boot automatically during an imaging.
Workaround: After signaling the device to re-image using either WDM/WMS and the unit restarts. Manually invoke the Boot Options (F12) and select Merlin from the list. This will start the re-imaging process for you. It is also possible to temporarily re-order the boot order to go to Merlin before the SATA drive (just remember to reset the boot order afterwards).
Recommend using 0A38 until the issue is resolved. I did have difficulty with the BIOS not downgrading once it is updated to 2.0F.