so I disconnect it at rebooted the screen.

What does this mean? Did you disconnect something, or just reboot? I'd try disconnecting the battery so that the Mr12Volt restarts as well. Next I would disconnect the display cable from the Mr12Volt and connect it straight to the display. Obviously that would require disassembling a bit of the dash board.

 

I disconnect the mr12volt and connected the screen again to original. But the screen was the same, so I was wondering if i have to get a new screen or it could just be some wires?

 

So it sounds like with the original connection you have the problem AND you have the problem when the Mr12Volt system is displaying. I would guess it has something to do with the screen at that point. You should probably have 3 different cables, right? I have the original cable and the two that came with my Mr12Volt. You can try swapping those with the original setup to rule out a cable issue.

 

I don't think I can swap out the original cable, because I have to plug it into the mr12volt to get the screen to light up, but i don't think this has anything to do with the mr12volt, it is probably the screen that is fried, or the cable to the screen that is broken.
But I think I just have to try and change one of them, and hope it works.

 

There is a cable from the CCC unit to the Mr12Volt, then a cable from Mr12Volt to the CCC display. Originally there was just a single cable from the CCC unit to the CCC display. You should have multiple cables and I think can swap any of them in to run directly from CCC unit to CCC display.

The Mr12Volt system has a display switcher that either passes through the original signal from the CCC unit to display the OEM content and then internally switches to its own video source when running things such as CarPlay. So Mr12Volt needs to have input from the CCC unit.

 

Yes, i did all of this, but i think when I connected the mr12volt, maybe the video card in the ccc screen was ruined, but I'm not sure, I've just seen some other people who had the simular issue, but not quite the same.