Is your game booting up? You can start and play a game? Check and report the 5v, 12v, and -12v at the top right of the (original DE) power supply.

Can you press the menu button on the far right on the ColorDMD and post a picture of the screen with the info?

I have the same problem as you. I bought an LED display and installed as per requirement but nothing shows on the display when switched on. My game boots and plays as well.

Dmod is his 12Vunreg high enough?

As above, please measure you voltages on your power supply and report them. Do you have anything on the display when you press the far right menu button?

If the ColorDMD has 12v & 5v. Did you add any new ribbon cables?

I have seen this with new cables.

Do you have another dmd you can put back in it to see if it works?

You don’t have to mount the DMD just hook-up as a test...

I tryed to install a color dmd in my old guns and it would not work with the rottendog power supply I had in the game,I don't know if this helps but all was fine with the stock display and then I moved the color display to a different game and it worked great.

Good luck

Are you sure the connector from the ColorDMD interface board to the LCD panel didn't come loose when the other one pulled away? I'd check both ends of that connector. It's extremely fine, and you need to move the little ends on each side to lock and release them.

Correct, the Rottendog power supply will not run the DMD in the game. Find a good original and go from there.

John

Yes, Rottendog boards i have had many, many problems with. I love new boards in my games but have learned over the years that many times right out of the box to have issues. Watch who you buy from because allot of time instead of fixing the problem they just try like heck not to get it back and replace it. Every time I’ve had a problem with the color DMD, Randy has really stepped in and helped. May take us a day or two but he seems to be able to track down the problem and most the time I feel stupid on the other end. However you have to make sure it has the 12v and the 5v or You’re just spinning your wheels. As far as I know the original DMD doesn’t use 5v’s. Also just to keep in mind I’ve had issues when I’ve had a few mods hooked up and the color DMD. This is the case you might look at installing an external power supply with 5 V and 12 V. It’s a piece a cake just time consuming.

First things to check...

(1) Make sure you have 5V at the Whitestar display board 2-pin power connector
(2) Make sure you have 12V at the ColorDMD power connector between the gray/yellow and black wires, and 5V between the gray and black wires.
(3) Check for a reversed data ribbon cable at the Whitestar display board. Red stripes should be closest to the corners of the board. Make sure the cables are seated properly with no bent pins.
(4) Press the button furthest to the right on the ColorDMD and make sure next to ROM FILE it says GNR 3.x

EDIT: Rereading thread, looks like you checked (1) and (2) already. Pressing the button furthest to the right as in (4) should always bring up menus (even if video from the game is not working). The menus are locally generated on the ColorDMD board and should work regardless of the video input. If that's not happening, either the firmware did not install properly or there's something wrong with the button connection to the large chip in the middle of the ColorDMD board. Make sure the STATUS LED is off and lights whenever any of the four buttons are pressed.

Time to start buying XPin power supplies when available. They have much better reliability and initial quality out of the box.

That is what I was going to do but out of stock at the time,then sold the game.

I uploaded a GNR DMD Install video to my YouTube channel. Maybe you want to watch the vid to make sure everything is in the correct place? After installing the DMD worked perfectly. Good luck

YouTube Video :

Blog Post :

https://pinballsupernova.wordpress.com/2016/03/15/mod-install-colordmd-install-and-game-play-of-data-east-guns-n-roses/