On some motherboards the boot block can be reprogrammed. It is dangerous as any issue during BB programming can kill the motherboard. Usually, there is a jumper on the motherboard that protects the BB portion of the BIOS. Set the jumper to not protect the BB and force the BB to be programmed. It looks like the Z420/620/820 has a jumper for this, but it appears many have tried to reprogram the BB with no success. Except for one fellow in this thread:
Solved: z820 e5-2600 v2 ivy bridge upgrade - Page 7 - HP Support Forum - 5086052
Look at the last two pages for posts by SalSimp. I don't think I am up for removing the BIOS chip and programming it in a flash programmer and soldering back on the board, but it worked!
Solved: z820 e5-2600 v2 ivy bridge upgrade - Page 7 - HP Support Forum - 5086052
Look at the last two pages for posts by SalSimp. I don't think I am up for removing the BIOS chip and programming it in a flash programmer and soldering back on the board, but it worked!