Flickering and flashing can be caused by two things that come to mind.

One the Hz is wrong. American and European video signals are not the same.

Second is from something I remember reading on the forums a long time ago. It had to do with powering the camera off the rear lights. It was either the source itself or the computer doing the bulb check it does that was causing the video signal to go nuts. IF that's the problem you can diagnose it by providing a clean 12v power source like connecting to the battery itself long enough to see if the problem goes away.

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