While I was doing bios mods on a R9 290, I managed to bork Windows. I initially believed I had a bad flash, and dropped in the 480 that I had laying around. From what I could gather afterward, the problem was in windows possibly registry? (I had issues also running my V56), and nuking windows cleared up problems with the 290 and V56. My 480 however, now will not POST, and when run with display from the 290 or V56, will post, but black screens while Windows is loading, and upon restart with the 48-0 removed, goes into startup repair, though after restarting, everything seems okay. I have been able to successfully boot into WinPE, as well as DOS in an attempt to blind flash a clean 480 bios. In DOS, ATIflash (the older version that's is DOS compatible, v4.17? something like that), was unable to find any adapter at all, V56 or RX480. In WinPE, I was able to boot with both cards installed, however, I have been unable to find a combination of WinPE and ATIFlash versions that are compatible, since running atiflash/amdvbflash always results in a "versions are not compatible" (Have currently tried WinPE1709 and atiflash v2.77, v2.84, v2.93) I attempted the shorting 8+1 on the bios chip to no avail, same black screen issue as initially. On an intel system using IGP, using the bios trick permits a boot into windows, however, no version of ATIFlash can see the 480, attempting to -f, or even grab info results in "adapter not found". GPUz, HWinfo, and device manager all do not see the card. The cards fans always spin up when powered, and Vcore, and Vmem are present on the card.
Any help is appreciated