iMac Intel 27" A1312 EMC 2374 i7

iMac powers on and chime sounds, the display can be seen to power on and remains black the entire time, checked with flashlight and nothing is seen.

All of the LED's are lit, I can connect to the unit remotely and share the screen, I checked the system profiler and find that the video card is detected. I find that if I go to the display preferences and adjust the screen brightness you can see the backlight adjust as its supposed to.

I tried reset all settings

I tried re-seating the video card

I tried swapping backlight inverter and LCD with Known good hardware same result

video card is my last step but i just wanted any suggestions before i shell out the cash

thanks