Put the Dell OEM GTX 1060 back in so you can boot into BIOS and disable Secure Boot. Then try your 3rd party graphics card.
Hi all I just got the Aurora R7 second hand, it came with the standard i5 8400, 8gb DDR4, GTX 1060. I pulled my AMD Radeon 7970 Dual-X oc ed from my old desktop and fitted it in the Aurora R7. At first it worked but now I get no picture at boot to access bios. I run Windows 10 and macOS Catalina dual booted with clover and all installed on Gpt disks using UEFI. The Aurora R7 Bios upgraded during first boot and setting up and updating drivers and stuff. It was in legacy mode just booting Windows 10. I changed a few bios settings, switched to UEFI in bios, set it up for booting macOS, etc, I also without thinking enabled Secure Boot. Now when i boot i get no picture at all from my radeon,. If i put the 1060 back in it works great, but nothing from the radeon, ive reset bios,. Removed battery etc, still nothing, not even in legacy.  I put my radeon back in my old system, boots fine and works no problem in uefi with secure boot on or off. Can anyone please advise, what can i try next? I really like the 1060 however Nvidia cards, pascal,. Will not work on macos, no drivers or support so i really need my radeon working in the R7.  Im so frustrated, this R7 is a complete mystery.
Aurora R7, AMD Radeon 7970 Dual-X