Through Dell Command Update I was prompted to update an OptiPlex 7040 with BIOS version 1.18.0. However this failed to apply and won't recover, just re-loading the BIOS recovery menu each time. I have tried:

• Recover BIOS, Reset BIOS, Rollback BIOS from the recovery menu
• Loading the 1.18.0 and previous version 1.17.0 from USB
• Removing the CMOS battery
• Swapping the jumper to CMCLR 

No matter what I try it fails to apply or reset, instantly erroring on 'BIOS update failed. Rebooting your System' on the first flash progress bar, never moving from 0%.

Has anyone any further suggestions?