Gigabyte HD 7970 no power


Jan 7, 2013
Just installed a new gigabyte hd ati 7970 and when I turned the pc on I noticed the fans are not spinning at all and the pc is not booting.I also upgraded the computers cpu and think something might be wrong with the cpu install.Would the pc cpu,if it was not working cause the video card not to work also since the cards fans are not spinning,all the other fans in the case spin,nothing at the 7970 card.I put one of the origional cards back in a ati 5770 and tried to boot and no boot but the 5770 fans are going though.Anyone have any ideas.I will keep plugging away for a while and if not fixed I will take my pc to the computer place where I bought the 7970 card,and the intel cpu and have them look at it.


Aug 19, 2009
I agrees EzioAs.
if your original 5770 works but no boot, you should check CPU installation first.
You also need to check the connection of 6/8-pin power cables to graphics and the max wattage of your PSU supporting hi-end card.


Mar 14, 2013

Did you find a solution? I have the exact same problem. I just purchased an ASUS Crosshair V Forumla-Z Motherboard and an AMD FX-8350 CPU along with a new Corsair Case, and I moved my two Gigabyte HD7970's over to it (these are about 3 months old and worked fine in my last PC) and am experiencing the same issue. I moved my HDDs and PSU (CoolerMaster 1000W 80 Plus) over to the new case also.

When I power on the PC the Noctua CPU Cooler fans start and the system powers on, I can see the Mobo's Q-CODE LED displaying numbers as it POSTs. It eventually changes to "99" on the LED which in the manual says "Reserved for future error codes".

The fans on the 7970's are not spinning, they appear to have no power. I have the 24-pin, 8-pin and 6-pin mobo power connectors hooked up, and also the additional ez-plug power cable that ASUS recommend for multi-gpu setups. I also have the PCI-E Power connected to the GPUs.

I removed the 7970's and installed one of my previous 5850 cards which had never had an issue in my old computer. The 5850's fans spin when the PC is turned on but I still get no video and card sounds like the fans are running at 100%.

I did fine one forum where someone said he went back to the stock AMD CPU Cooler and fixed a similar issue. It makes zero sense to me that it'd work, but I figured "What The Hell?" I removed the Noctua cooler and installed the stock AMD cooler. The PC then booted and the 7970's got power. In the POST I received a message that the BIOS defaults had been loaded, which I also noticed had set my 2133Mhz DRAM back to the stock 1333Mhz. I've left the DRAM at the default for now as the system appeared to be working.

However, whilst playing the new Tomb Raider game for an hour or two the fans in the case were very loud and I could feel the air coming out the top was much hotter than I've felt in a long time. I quit Tomb Raider and ASUS Probe alerted me that the CPU was over 65 degress.

I've pretty much left it as it is for now as I had to get to work. I'm not convinced swapping the CPU Cooler fixed the issue, but one thing is curious. The stock cooler has a 4pin CPU Fan connector, as does the motherboard. The Noctua cooler is only 3 pins, but the guides/tabs on the mobo connection allow it to be connected without issue. And both fans on the cooler have power.

In the BIOS I noticed there is a setting to tell the mobo whether the CPU fan has a 3pin or 4pin connector, however I havent had time to test that setting with the custom cooler yet.

I'm thinking it could have something to do with that setting, and also with the DRAM (which is 16GB Corsair Vengeance 2133Mhz) as swapping the CPU cooler defaulted the memory to 1333Mhz, tho not sure this happened or whether it is related.

On a hunch I've ordered a new Corsair Corsair HX-1050 V2 80 PLUS Gold Power Supply and will install that on Monday when I receive it and see if that improves thing. My current PSU is about 6 years old so it can't hurt.

This is a head scratcher.