Hola, I just bought two weeks ago a flashed 6800 to put in one of my quicksilvers G4, the problem is that the card is 8x agp, so i have to tap the 3 and 11 pins, but after the mod, the Mac boots but the screen becomes black after the grey screen with the apple logo. The seller told me that the card is in good condition, cause it displays the initial screen with the logo, but i dont know why the mac does not continue the load of the system. i have try the operation in other quicksilver and with other hatd disks and the problem is the same. anyone have found the same issue? thanks a lot.