if you have absolutely nothing, its prob not gassed. usually its gradual and gets distorted. if yours is completely blank, id say prob a power supply issue on yours.

every data east and sega ive owned, its been a power supply issue, i think im at 6 or 7 now! no kidding!

You actually need to test the voltages at the DMD power connector. -112, -100v and 68v are very important for the DMD to work.

http://www.pinwiki.com/wiki/index.php?title=Data_East/Sega#Testing_DMD_HV_Power

You can buy the LED ColorDMD now for JP, as it would include everything you need for it to work and fit into LAH and you would not have to worry about the High Voltage on your power supply as it would not be needed. Then you only would need to wait for it to have the color ROM file updated, hopefully this year, and you would have a full color display. I am looking forward to this title having full color.

http://shop.colordmd.com/led-replacement-display-for-jurassic-park-pinball-machine/

power supply board.

I do mean on the power connector of the DMD, just as it showed in the link on post.4. This is going to the best location for the voltages as it has to go through 2 connectors from the power supply to reach the DMD. It would be good to wedge the black meter lead between the ground braided wire and the wood of the backbox so you don't have to worry about holding both meter leads. Pin 1 is on the left looking at the power connector as you see it in the picture.

2018-04-14 23_44_28-File_TestingDMDVoltagesAtTheDMDConnector.jpg - PinWiki - Internet Explorer (resized).png
2018-04-14 23_45_15-Data East_Sega - PinWiki - Internet Explorer (resized).png

My JP ended up needing a new CPU board. I tried a rottendog dmd controller but that did not help so I found a cpu board, swapped it and the dmd started to work.

Did the DMD ever work for you? Can you post a picture of the boards and the back of the speaker panel (with the DMD controller) with the game on please? So many other possibilities being MPU, ribbon cable, DMD, or even the DMD controller board.

Also do you have access to a friend's DE machine to be able to start with testing the DMD controller and DMD?

In that case, I guess it is possible a ribbon cable somewhere is half way out. May even try to reseat all the ribbon cable connections. If that does not help, try gently wiggling the ribbon cable to see if that has an affect on the DMD.

Also, possible the display ROM on the DMD controller board may not match up with the new game ROM. May go back and try the old game ROM again to see what happens. What version is the old game ROM, new game ROM and Display ROM?

Any chance you had installed the display ROM backwards and applied power? If so, likely would had killed the display ROM.

Move your display ROM over to the ROM 0 location since it is marked as 'Disp 0'.

Then I would try the old display ROM in ROM 0 to see what that gets you.

Awesome. As I mentioned, many...many possibilities for a failure sometimes. That one was not even on my mind. Time to get ready for that LED ColorDMD.

Let's see a picture of the working DMD.

Well, for LAH, the LED will only be the publically supported display by ColorDMD because of the speaker panel. If you are willing to modify the speaker panel a bit, the LCD will fit, but it may block an inch of light at the bottom of the translite as it would stick up pretty high in the backbox. Also, the LCD will sit pretty far back so you'll have to add something on both left and right side of the display to block the light from inside the backbox. If you do modify it for the LCD, you will have to get the color ROM from ColorDMD as it would be supplied as needed. I do prefer the LCD, but I'll likely go with the LED in my JP once I get my project game working. It is a ways off right now.

After 4 years, I finally got my LAH set up so I can start working on a MPU board for it. Since my game is missing a DMD, I just ordered the JP LED ColorDMD for it in hopes full color will get supported for this game this year. If nothing else, I can choose what color the display will be until that time comes. I'm thinking yellow or light blue would look pretty nice in this game. LAH (resized).jpg