I am having a problem with several 7040 Optiplex PC's. When booting up I do not see anything on the screen. No DELL logo, no option for F2, F12, etc. I know that the computers are going through the post boot process because they give me 1, 3, and then 2 beeps when I remove the memory. After reinserting the memory and booting up, I can see that the keyboard numlock light works after giving the PC enough time to go through the post boot process. I can also see it going through the process of booting to a USB flash drive (W10 installation drive) during the bootup process. But nothing on the display monitor.

I have tried a HDMI to VGA adapter, Display Port to VGA adapter, and USB to VGA adapter. I have even tried inserting a PCI-e video card and still nothing. I have also tried the Display port to VGA and the USB to VGA adapters in various ports on the PC. I have removed all cards, memory and the battery and held down on the power button to drain the bios of all power.

Any suggestions? Is there a function key or key combination that will force these PC's to boot to a certain port (ie: display port1)

Thank You

David