Well, I'm not an expert, but I think it's very possible that the color DMD and LED strips are overloading the 12v line. My fuse blew out just like yours when I added a color DMD. I also have LED strips on mine, though under cabinet. Regardless, the only thing I could do was power the LED strips and color DMD off its own power. I tapped into the game's main power line and added a switched outlet. That solved my issue. I've heard of others having 12v issues with a color DMD, but can't comment too much on other resolutions without some searching.

Have you tried disconnecting the LED strips and seeing if that helps? Those don't draw much power, but it might be just putting it over the edge and/or help to narrow down if it's really the cause.

Yep. I'd move the colorDMD to its own power supply. Pretty easy to make one for about $10 total. And if you cut off the plug on thrower supply and twist it into the black and white wires from the power switch to the coin door, hen the extra supply will power on and off with the game.

Here these are super cheap: http://www.amazon.com/Power-Adapter-Supply-2-1mm-CCTV/dp/B00452YFZU

And you can make a connector using this: http://www.pinballlife.com/index.php?p=product&id=1593

You only need two of the prongs.

Happened with my IJ after adding LED strips in combo with the ColourDMD. My solution was to hook up the LED strips to a 12V power supply fed through the vent in the back corner of the cabinet. I quite like having it seperate as I can turn off the LEDs alltogether if i want. Also, my wall wart has variable voltage so I can dim the LEDs if I want.