From my experience with my LW3 it is normal for the DMD to occasionally not light up immediately on power up. I can't say why but its been like that for over 2 years without any problems whatsoever. The DMD just skips over showing the ROM versions of the CPU and display driver and FREE PLAY or PRESS START is the first thing to be seen. LW3 has the exact same board set as Star Wars. I wouldn't worry about it.