I am attempting to install my newly acquired 2080Ti Black Edition (11G-P4-2281-KR) into a slightly older system, replacing my failing 560Ti.  I realize that this is not a particularly performant match for the rest of the system, but I am attempting to put off further upgrades for a little while longer.
 
Unfortunately, I am having trouble with the install; in short, the UEFI/BIOS post beeps seem to be complaining that there is no graphics card installed when I boot up (5 beeps, no output to monitor).  Further, the onboard "Dr. Debug" boot reporter seems to be indicating that it remains in the "OEM pre-memory initialization code" part of the boot-up (29).  The card itself does light up as you'd expect, and the fans do activate.  The card is firmly seated into the slot, and the slot latch snaps into place properly.
 
I have already replaced the PSU with a new and verified working unit (850W, PSU tester and multimeter readings under load confirmed good).  I am able to put my old 560Ti back in, and the machine boots up properly.  Additionally, I am using the same PCI-E connectors when switching between the cards, so I'm confident neither power nor connectors are an issue.  I have tried both with and without the powerlink adapter I need for my case, and that does not alter the outcome.  I have also tried putting the card into a different PCIe slot, but the result is the same.  Interestingly, depending on how I reboot/reset the system (reset vs. power button hold), I sometimes do get the UEFI setup boot menu screen, but am unable to access it (MB still reports same boot-up phase (29)).
 
I've searched around a fair bit online (before I bought, even), and I have seen a scattered few folks querying about compatibility with 2080s and older Sandy Bridge motherboards, and I didn't see any explicit "that won't work" issues, either with P67 MBs in general or mine specifically.
 
Has anyone else tried installing a 2080 into a Sandy Bridge/P67 MB system?  Any thoughts on things to try?  Or, generally, what kind of incompatibilities might cause such an issue?  I suppose it's also conceivable the new card itself is bad...unfortunately I don't have another system to put it in to test.
 
Motherboard:  ASRock Fatal1ty P67 Professional
CPU:  Intel Core i7 2600k
RAM:  16GB
HDD:  3TB
PSU:  eVGA Supernova 850 T2 (new)
OS:  Windows 7 Ultimate Professional 64-bit
GPU:  eVGA RTX 2080Ti Black Edition Gaming (11G-P4-2281-KR)

Great graphic card, great PSU.
You now need only to upgrade platform on i7-8700K + EVGA Z370 Micro or Z390.