This is so crazy.
I have bought a Radeon HD 7870 to upgrade my graphics (HD7770)
Whenever I put it in, my PC wont boot. Light turns on on PC; fans run, but black screen and it doesn't boot up. (made sure to make sounds in windows startup to see if it was just a monitor issue or something, but it doesnt even boot up, just stands there with fans running.
I purchased a second 7870, as I thought the card was DOA, but it was exactly the same issue.
I tried putting back my old 7770, and it booted up without trouble.
I then looked at the internal parts and figured it might be PSU/MB/BIOS/CHIPSET updates.
My PSU is a Corsair GS600Watt, so should be more than enough power + it works flawlessly with the 7770, so I guess that's out of the Q.
The BIOS was an old HP bios and I could not find an update. So I found a new simple Asrock H61 MB with PCI X16 port for the gfx and bought that, hoping it would resolve the issue.
SAME EXACT THING happened.. The PC won't boot up. Whenever I switch the cards back to my old 7770 it works without issues..
So now im pretty baffled.. can it be?? Did I get 2 cards sent to me, both DOA? I highly doubt it. What can it be? I even tried removing/switching ram blocks, cleared CMOS, everythign!?! but no fix.