I currently am working on a DE Star Wars machine. The CPU boots completely and the game plays fine, but there is no sound or display on the DMD. When powering on the machine, both the sound board and the display board boot (sound: "may the force be with you" plays; and display shows the version number), then nothing. No display or sounds from that point on. I've replaced all fuses and ROM chips on all the boards and I have checked the voltages to the boards and everything seems fine.

Thoughts?

I am thinking there is a CPU issue, because the boards are booting but it appears that they are not receiving instructions from the CPU. I should add that I have checked all the cables to make sure they are properly installed (Pin 1 to Pin 1, etc.)

Any thoughts are appreciated!!

The ribbon cables are all connected properly and the voltages to the sound and display board are correct.

Yeah, I don't like the DE schematics either. I have fixed virtually everything on my star wars machine except the sound and display issues. I have a DE Test Chip and there is nothing wrong with the MPU. Plus, the game plays fine -- all lamps, flashers, coils, etc. work fully -- just no display or sound. I have concluded that there must be a problem with the display driver board and the sound board. Both have new EPROMs installed. And I have an extra display (that I know works), so I hooked that up that display to the driver board and still nothing (other than the initial version info 1.04). The sound board boots, playing the "may the force be with you" sound, but then it does nothing else. Interestingly, if I plug in the ribbon cable from the sound board into the MPU (and yes it is plugged in correctly - Pin 1 to Pin1), the game won't boot. There must be something wrong with the sound board then. What, I do not know. I have pulled the driver board and sound board from the machine and after I finish shopping out the rest of the machine, I will turn my attention to these 2 boards and see if I can figure it out. As always, if you have any ideas, please let me know!!

Come to think of it, perhaps I should try new ribbon cables first before I go messing around with the boards.

I bought the EPROMS (from Marco, I think). I have not checked them to make sure they are not corrupt. But, I was having the sound and display issues before I replaced them, so I figured they must not be the problem.