Just for information, in case this catches anyone else.

A couple of weeks ago I ordered the components for a new computer including a Gigabyte GA-Z77-D3H motherboard and MSI Geforce GTX 660 graphics card. After putting it together I found the system failed POST (didn't get as far as lighting LEDs on the keyboard). With an older NVidia card in the PCIe slot everything worked fine. The PSU was a new Seasonic G-550 so unlikely to be the problem.

Overclockers support thought that the card was probably DOA so I sent it back. However it tested OK and they sent it back to me. Still didn't work in the new system though.

Eventually I tried updating the motherboard firmware from F8 as supplied to the current F18 version and happily this resolved the problem.

Bottom line: the GA-Z77-D3H with older firmware versions seems to be incompatible with the MSI GTX 660. Might apply to other GB motherboards and GTX 660 cards as well, of course.

seems to be happening a lot with other cards and anything ivybridge chipset orientated too!

6950s unlocked wouldnt post, 7750 too.

Hopefully its just buggy bioses. thanks for your input.

This is common and theres been a few people who have needed to do a BIOS update top get the GFX card to work, luckily it seems to fix it.

If you had asked here what possibly could be wrong before sending the card back then I would have immediately suggested flashing to the latest BIOS.

I built a system for a friend today using the Z77-D3H motherboard, with a 3570K and a GTX660.

I too get this problem where I can't post with the graphics card installed but on-board works fine.

I tried updating the bios to the latest F18 but I get the error File size incorrect or too big, can't remember exactly. Not sure how to get around this.

Silly me, I didn't extract the zip file, after I did it worked fine.

Updated to F18 and the pc boots now with the graphics card installed.