UEFI issue on Optiplex 7010

We're experiencing a lot of issues with our Optiplex 7010 systems: blank screens, no system reaction. Solution is a mobo replacement...

On an affected system, the issue is reproduceable:

• enter UEFI/BIOS Setup
• General => boot sequence => Boot List Option = UEFI
• General => Advanced boot options => enable legacy option roms = OFF
• save settings
• reboot system => blank screen, no system reaction

Solution: reset BIOS with jumper on mobo + do not disable legacy option roms

Tested with BIOS versions A16 and A18

Behaviour does not occur on all systems!

Questions:

• Does anybody have similar issues? We have a dropout percentage of over 10%!!!
• Are there different mobo models in the Optiplex 7010 systems?