Have a HD4870 purchased end of 2008 but was just tested then and unused till August last year when my other one was damaged in a house move.
It has been working great till I had to remove it to connect a cable to the IDE port at bottom of motherboard under the pci'e slot
Since I put it back it it has a problem working, first one is that it wont turn on first time, or in other words pc gets power to all components but nothing appears on screen then you have to wait about 5 minutes then turn power off at mains or button on front then as soon as you press it again the pc works.
Everything is working and the temperature is low but any games or emulators using D3D just crash and wont work even after a full reinstall of Windows, yet use the onboard graphics and they work.
Any ideas to the fault?