Give us a run down of your PC specs and any codes that maybe involved or the number you are getting.

x99 FTW K
i7-6850k
16gb corsair dominator @ 3200Mhz
2 GTX 660 SC sli
samsung 500gb SSD
WD 1tb HDD
 
Ill re seat the the graphic cards when i turn my computer off and let them cool down.
There are no codes other then the normal one when it posts. when it dosent display the screen it is just showing the CPU temp on the LED debug.

Ok ill check it in bios, although the Nvidia control panel says it recognizes it and it is in SLI.
I wouldn't be surprised if it is problems from one of my graphic cards as one of them the dvi port when used is artifact central.

Just in case, you might want to plug in the PCIe power header on the MB if the problem persists and go from there after everything has been tried and make sure everything is running at stock settings.

Make sure your PCI-E lanes are set to GEN3 mode and not AUTO. Make sure your display cable is connected to the first gpu (closest to cpu).

ypsylon
Just wild guess, but let me guess anyway - is VGA connected via DP to the monitor?
 
I had same problem at some stage. Black screen until Windows landed on the desktop (sometimes even longer). Returned to DVI and never looked back. If by any chance DP is the culprit here, it's known issue like since forever and still isn't fixed. The only known solution is to unplug cable from card and monitor, wait a good while and plug it back. It will reset ports, but nothing will prevent from doing exactly same thing after reset/shutdown. Infuriating doesn't even come close...

That's a great tip ypsylon. carriliok, have you solved this issue yet? if so ,what fixed it?

I had a similar issues with my new build same cpu and mobo as you. It ended up being my older monitor while using the HDMI cable... would cause the board to hang at post code 62 after a reset of the cmos. I had to be on a different input then switch back to the hdmi after the system got to the cmos checksum error. I could then get into bios and configure the system. After, I couldn't get into the bios it would just black screen unless I switched inputs, then went back to HDMI when I saw post code a9 which meant it was in the bios.
 
Once the OS was installed it booted into Windows and the system functioned normally, just couldn't get in the bios without switching inputs. I solved this by buying a new monitor and the issues is gone.

carriliok
I switched the cards around an in bios it says t recognizes both (says x16 gen3) on the two slots that are occupied but when i post and load into window it is only recognizing the card in the first slot. the LED pci_e readout is not lighting up for the second x16 slot and only shows the first slot. is the Gpu dead?

Well then indeed it maybe the problem with a card. Disable all other unused slots with DIP switch to eliminate possibility of faulty lane negotiation. Classy had that issue early on. It never hurts to try on FTWK.
 
Unfortunately FTWK does not offer troubleshooting mode with Turbo switch which is available on Classy.