Do not under any circumstances unplug the dmd while it is on. This is specific to gottlieb's as it can and will blow the u8 gal chip.

With that out of the way. First check that the pins for the ribbon cable and the dmd power plug are clean with the game OFF. Try disconnecting the plugs and reconnecting them multiple times. If they are really dirty clean them up first.

Try it now, does it stay on? No? Then open up your starship troopers and use the ribbon cable from its dmd in street fighter. Ribbon cables go bad and if it has a broken wire it can work if its in the right position. If this fixes it order a new ribbon cable. If not you eliminated it as a problem.

If it still doesn't work wait for it to fail again, open it up and measure the power at the dmd power plug.

Start there and if the connectors, ribbon cable, or power are not the problem there are other things to try. If it is a power issue then someone who still owns a gottlieb can point you to where you can check the power going into the dmd driver board to see if its that or if the board needs a rebuild kit.

Not ignoring you on this, but since I no longer have a gottlieb so think its best for someone who has one to refer you on next steps.