Please upload bios backup here for this model to build new bios HP MP9 G2 Retail System BIOS HP EliteDesk 800 G2 DM System BIOS (N21)
HP elitedesk 800 g2 Spitfire Rev A bios problem No display fixed https://bios-fix.com/index.php?threads/hp-elitedesk-800-g2-bios-problem-no-display.51315/