If you dont get a WHITE screen, it means your graphic card is still working somehow. White screen means that there is 0 signal.
Check/Jiggle point where the two cables from the monitor connect to your motherboard and VGA card. (there are 4 cables coming from the LCD panel, 2 thin round wires for the wireless antenna, 1 video cable and 1 power cable).
Try to plug another monitor to your laptop on the VGA port and do FN-F8 during boot. Hopefully you'll see things appear on the external monitor. If not, then your mobo might be dead. Not the graphic card.
To be sure the mobo isn't really dead, let your computer boot up. Look at the LED light for the hard drive, if it flashes randomly, it means your hard drive is being read, meaning something is loading, meaning your motherboard is fine. The HDD LED is left the wireless LED and right of the NUMLOCK LED. Or simply, the 3rd LED starting from the power button, going left.
Finally, I'd just take apart all that I can and piece if back together one by one to see where things fail. The Z71V is a very sturdy laptop, it can take quite an abuse without breaking, so don't be shy. My graphics card have been so abused that the PCB board is not flat
It is actually caved in and it still works 100%