I'm sorry to hear that you're having this issue.
Your unit may require technical service, but first, let's see if we can do a quick troubleshooting idea.
If you have access to the lamp panel, unplug the television, open the lamp cover and remove the screws that hold the lamp in place. Pull it gently, and then push it back in firmly. Re-tighten the screws, replace the lamp cover and then plug the TV in. If it fires up, that may solve your issue. If it doesn't, then I might suggest calling 800-SAMSUNG to have your unit serviced.
Sometimes just re-seating the lamp can fix the issue.
I have a Samsung 56 inch DLP TV. It started about 1 year ago turning itself off for no apparent reason. It is now doing it at least every 1/2 hour when we are watching tv. The green light goes off and the red light comes on. Any idea's as to what might be wrong?