I just received my new Gigabyte 7970, but when I install the card I get no signal on my monitor. However when I plug in my old 5770 everything works fine. My current motherboard, however, is Dell manufactured from a brand computer.
I've already tried updating my BIOS, reseating the card, checking plugs.
Intel Core i7 2600 @ 3.40GHz
Radeon HD 5770
More about7970 signal
Have you tried inserting your card into other slots?
The motherboard im using only has one PCIe slot at the moment
if the fans are turning on at max RPM, then try using different power connectors.