Is there a hdmi port or a dvi or vga that you can hook it up to an external monitor to see if it will work that way ? this will tell if the screen itself is the problem . You may also want to try removing one stick of ram at a time to see if the issue is with the ram.
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You could also try doing a static discharge. Unplug the computer and then hold the power button down for 60 seconds then plug it in and try to boot
. Hope some of this is helpful