Mhmmm ... the card boots (only on HDMI ... DVI and DP are dead) and when the windows-driver tries to initialize the higher resolution, it flickers shortly and reverts to 640x480x16 with a driver error (driver tries this two times before giving up).
I thought this could be a power problem, because the image is ok on lowres (safemode).
I have found some burnt caps (the small ones) near the drMos chips, but everything else looks fine.
Probed all fuses, shunt-resistors and drMos (vin against gnd), all coils and the 470's caps ... all of them having similar values. None of them are shortned or open ... coils are low on resistance, but i think thats normal.
Also checked all phases against gnd ... no short at all.
Probably there's a fault on a component under load.