I'm new to this. I just bought a used Barco 600 DATA. I plugged it in and turned it on. The fans run, the LED's light up,the video switch on the back is on, the three convergence switches inside are on, but there is no beam comeing out of the front. No projection. Am I doing something wrong? I don't have any thing hooked up to it. I just wanted to test to see if it works. Does something have to be hooked up to it? Please Help. Thank You.