I just recently started building my new rig. It has a 780i motherboard, a 9800GX2, 8 gigs of ram and a BFG ES-800 power supply. The thing will not boot, display anything on the monitor, or even make system beeps. The fans spin up, leds light up on the motherboard and it displays "FF" on the debug LCD which stands for "Boot". Whats going on?
Well my first suggestion would be to pull out some of the ram. You've got not only the 8gb of system ram but I believe another 1gb on the 9800x2. I believe its the OS that actually addresses RAM but since the large amount of ram is what sticks out in this build, start your troubleshooting there. See if it will boot with the 9800x2 in and just 2gbs of ram. If so keep adding ram until it won't boot anymore. A second thing to try is booting with another, single gpu, video card. The thing to do after that is swap out the power supply. Just 'cause you get spin up and everything looks good doesn't mean its supplying the wattage it should be.
After that, you if you have another cpu that fits that socket you can swap those out. A dead cpu will stop a board from POSTing. If all those things fail to fix your problem you need to consider you may have a bad board and start an RMA process.
Hope my suggestions help!
OK, I finally got it booted. Everything seems to work fine except for a few little things that I will fix later on such as reapplying Arctic Silver 5, but for now it will do. About the power supply though, I thought the ES-800 was suppose to be a better power supply? I read the review on Tom's Hardware and it appeared to be well liked. I have had bad experiences with OCZs and I have used Enermaxs but I thought I would go with this one. Oh well. Lastly, when looking at Rivatuner to adjust fan speed on the GX2, it says there is only 512mb on the card that is clearly a 1gb card. Any reason why?
The GX2 has 512MB of RAM per GPU. It's 512MB dedicated to each GPU and not a common pool of RAM for whole card. Thats quite a bit different than a single GPU that has 768MB, 896MB or 1024 RAM for example.